WO2018152595A1

WO2018152595A1 - Ophthalmic lens system for controlling and/or reversing the longitudinal chromatic aberration of a human eye using a diffractive optical element

Info

Publication number: WO2018152595A1
Application number: PCT/AU2018/050173
Authority: WO
Inventors: Ravi Bakaraju; Klaus Ehrmann; Arthur Ho; Cathleen FEDTKE
Original assignee: Brien Holden Vision Institute
Priority date: 2017-02-27
Filing date: 2018-02-27
Publication date: 2018-08-30
Also published as: WO2018152596A1; TW201841024A; WO2018152596A9; TW201841023A

Abstract

An ophthalmic lens system that includes a lens having a first power and a first refractive index and a diffractive optical element. The lens and the diffractive optical element are selected such that when visible light passes through the system, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

Description

OPHTHALMIC LENS SYSTEM FOR CONTROLLING AND/OR REVERSING THE LONGITUDINAL CHROMATIC ABERRATION OF A HUMAN EYE USING A DIFFRACTIVE

OPTICAL ELEMENT

CROSS-REFERENCE

[0001] This application claims priority to U.S. Provisional Application Serial No. 62/463,942, filed on February 27, 2017 and entitled "Ophthalmic Lens System for Controlling Longitudinal Chromatic Aberration" and to U.S. Provisional Application Serial No. 62/599,408, filed on December 15, 2017 and entitled "Ophthalmic Lens System for Controlling and/or Reversing the Longitudinal Chromatic Aberration of a Human Eye" and is related to a PCT application (PCT/AU2018/ ) to be filed on or about

February 27, 2018 and entitled "Ophthalmic Lens System for Controlling Longitudinal Chromatic Aberration," each of which is herein incorporated by reference in its entirety. Provisional Application Serial No. US 62/412,507, filed on October 25, 2016, entitled "Devices, Systems and/or Methods for Myopia Control" and PCT/AU2017/051173, filed on October 25, 2017, entitled "Devices, Systems and/or Methods for Myopia Control" are each also herein incorporated by reference in its entirety. In addition, the article entitled "Physical human model eye and methods of its use to analyse optical performance of soft contact lenses" by Bakaraju, Ehrmann, Falk, Ho, and Papas, Optics Express Volume 18, No. 16, August 2, 2010, Pages 16868-16882 is herein incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] This disclosure relates to an ophthalmic lens system, for example, a spectacle lens system, for controlling or reversing the longitudinal chromatic aberration of a human eye, e.g., introduce a stop signal to a progressing myopic eye or an eye that is progressing towards myopia. This disclosure also relates, at least in part, to the reversing of the longitudinal chromatic aberration of the eye at the retinal level of a human eye, to deliver a stop signal that discourages eye growth. This disclosure also relates, at least in part, to the use of diffractive optical elements in conjunction with an ophthalmic lens, for example, a spectacle lens that is aimed to deliberately control or reverse the longitudinal chromatic aberration of the eye that may serve as a stop signal to retard the rate of progression of a myopic eye or an eye that may be progressing towards myopia, i.e. an eye which increases about or at least -0.25 D or more per year. The present disclosure also relates, at least in part, to the methods and/or systems for exercising the eye and inhibiting/controlling the progression of myopia using a regimen of spectacle lenses that introduce temporal variations in the reversal of the chromatic aberrations of the wearer's eye, for wavelengths corresponding to F-line (486 nm), e-line (546 nm), d-line (588 nm) and C-line (656 nm).

BACKGROUND

[0003] The discussion of the background of the present disclosure is included to explain the context of the disclosed embodiments. This discussion is not to be taken as an admission that the material referred to was published, known or part of the common general knowledge at the priority date of the embodiments and claims presented in this disclosure.

[0004] For an image to be perceived clearly, the optics of an eye should result in an image that is focused on the retina, particularly on the fovea. Myopia, commonly known as short-sightedness, is an optical disorder of the eye, wherein the on-axis images are focused in front of the fovea of the retina. Hyperopia, commonly known as longsightedness, is an optical disorder of the eye wherein on-axis images are focused behind the fovea of the retina. The focusing of images in front of or behind the fovea of the retina creates a lower order aberration, called defocus. Astigmatism is another type of lower order aberration, where the optics of the eye deviate from spherical curvature, resulting in distorted images, as light rays are prevented from meeting at a common focus. In addition to lower order aberrations, an eye may also have higher order optical aberrations, including but not limited to, spherical aberration, coma and/or trefoil.

[0005] In myopia, the visual focus defect is such that distant objects (items in the scenery being viewed by the eye) appear blurred because their images are focused in front of the fovea instead of being on the fovea. Myopia is a common visual disorder, affecting around a quarter of the adult population of the USA, and its prevalence is increasing. In some countries, most notably in the Asian region, the prevalence of myopia is now higher than 80% in school-age children. Thus, a large percentage of the world's population has myopia at a level that requires some form of optical correction in order to see clearly. Myopic refractive error is progressive in younger patients (i.e. the refractive error increases over time). It is also known that myopia progresses regardless of age of onset, and myopia tends to increase in amount requiring progressively stronger correction. High amounts of myopia can lead to permanent vision impairment, cataracts, glaucoma and some forms of retinal pathology with increased risk of, among other things, retinal detachment. In addition, accompanying this visual disorder are personal, social and financial burdens to the individual and to the community. These include the direct costs of vision correction and management (which amounts to several billion dollars a year), as well as indirect costs such as productivity and quality of life. The visual and potential pathological effects of myopia and their consequent inconvenience and cost to the individual and community makes it desirable to have effective strategies to prevent or delay the onset of myopia, to stop or slow the progress, or limit the amount of myopia occurring in patients.

[0006] Ocular system attains and maintains emmetropia (where the eye length is well matched to the focal length of its optics) by using the visual feedback mechanism to adjust the position of the retina in relation to the optics of the eye. The axial length of the eye is controlled by homeostatic growth control mechanisms that involve "grow" and "stop" signals. The ocular system relies on visual experience as a principal input for effective functioning of the homeostatic feedback mechanism. The error signals that can decode the sign of optical defocus aid an increase or decrease in the rate of eye growth to result in a minimal refractive error. Such a compensation mechanism has been repeatedly shown in numerous experiments, where the animal eyes compensate for the optical defocus imposed with the spectacle lenses, by adjusting the rate of the eye growth. Ametropia results in the event of a failure of such an active emmetropization process. There is evidence from the literature that defocus signals govern the emmetropization process. However, some recent literature suggests that longitudinal chromatic aberration may also offer cues to the emmetropization process.

[0007] Figure 1 offers the spectral sensitivity curves for short (S), medium (M) and long (L) sensitive photoreceptors of a human retina. The refractive indices of human eye's optical media are highly wavelength dependent, exhibiting significant levels of chromatic dispersion. The longitudinal chromatic aberration (LCA) of the eye is defined as the change in refractive power of the eye as a function of the wavelength, considered in visible white light (from approximately 400 nm to approximately 700 nm). The LCA of the human eye is approximately 2 diopters (D) (from approximately 400 nm to approximately 700 nm, Figure 2) and it relates to the measure of on-axis chromatic dispersion. Figure 2 shows the longitudinal chromatic focal shift in Diopters. The table in Figure 2 shows the focal shift for each reference wavelength with respect to 540 nm treated as the reference wavelength. The peak cone sensitivity for S-Cones is 443 nm which corresponds to a focal shift of -0.72 D with respect to the reference wavelength (540 nm). Similarly, the focal shifts from the reference which control and/or reduce the progression of myopia by introducing a stop signal. The current disclosure describes deliberate manipulation of the longitudinal chromatic aberration to deliver a reversed longitudinal chromatic aberration to an eye that may serve as a stop signal to the myopic eye or an eye that is progressing towards myopia. Certain exemplary embodiments are to ophthalmic lens systems that provide a reduction in myopia progression and/or other advantages and/or improvements as discussed herein.

[0008] There are several theories for why certain individuals become myopic. One such approach is that longitudinal chromatic aberrations may affect the development (e.g., growth and hence axial length) of the eye.

[0009] Accordingly, there is an unmet need for ophthalmic lens systems for controlling, partially controlling or substantially controlling longitudinal chromatic aberration to deliver negative and/or reversed longitudinal chromatic aberration to an eye. Exemplary embodiments may benefit from a reduction in myopia progression and/or other advantages/improvements as discussed herein. The present disclosure is directed to solving these and other problems disclosed herein. The present disclosure is also directed to pointing out one or more advantages to using exemplary ophthalmic lens systems.

SUMMARY

[0010] The present disclosure is directed to overcoming and/or ameliorating one or more of the problems described herein. Briefly, the longitudinal chromatic aberrations (LCA) present within the eye or within an eye wearing an ophthalmic lens may affect the development (e.g., growth) of the eye. There is a need for ophthalmic lens and/or lens system that may control the longitudinal chromatic aberration of the eye when an exemplary lens and/or an exemplary lens system is worn on the eye. The present disclosure is directed, at least in part, to ophthalmic lens and/or ophthalmic lens systems that may reverse, invert or interchange the longitudinal chromatic aberration of the eye and/or provide negative longitudinal chromatic aberration for the eye. The present disclosure is also directed, at least in part, to ophthalmic lens and/or ophthalmic lens systems that may substantially reverse, invert or interchange the longitudinal chromatic aberration of the eye and/or provide negative (or substantially negative) longitudinal chromatic aberration for the eye.

[0011] Exemplary embodiments of this disclosure relate, at least in part, to reversing the longitudinal chromatic aberration of the eye at the retinal level of a human eye, to deliver e.g., a stop signal that discourages eye growth. Some embodiments relate, at least in part, to the reversing of longitudinal chromatic aberration of a human eye for the wavelengths that correspond approximately to F-line (486 nm), e-line (546 nm), d-line (588 nm) and/or C-line (656 nm), to produce a stop signal to a progressing myopic eye. Some embodiments also relate, at least in part, to the use of diffractive optical elements in conjunction with an ophthalmic lens, for example, a spectacle lens that is aimed to deliberately control and/or reverse the longitudinal chromatic aberration of the eye that may serve as a stop signal to retard the rate of progression of a myopic eye or an eye that may be progressing towards myopia. Some embodiments also relate, at least in part, to the use of diffractive optical elements in conjunction with an ophthalmic lens, for example, a spectacle lens that is aimed to deliberately introduce at least 0.5 D of reversal in the longitudinal chromatic aberration of the wearer's eye that may serve as a stop signal to retard the rate of progression of a myopic eye or an eye that may be progressing towards myopia. Some embodiments also relate, at least in part, to the introduction of a stop signal to a progressing myopic eye by reversing the longitudinal chromatic aberration, for wavelengths approximately corresponding to F-line (486 nm), e-line (546 nm), d-line (588 nm) and C-line (656 nm), using a spectacle lens and/or a spectacle lens system that is independent or substantially independent of the wearer's viewing angle through the spectacle lens and/or the spectacle lens system. Some other embodiments also relate, at least in part, to provide a therapeutic treatment for a progressing myopic eye by controlling or reversing the longitudinal chromatic aberration, for wavelengths approximately corresponding blue, green and red wavelengths using a spectacle lens and/or spectacle lens system. Some embodiments also relate to methods and systems to be used in conjunction with the eye for inhibiting/controlling the progression of myopia using a regimen of spectacle lenses that introduce temporal variations in the reversal of the chromatic aberrations of the wearer's eye, for wavelengths corresponding to F-line (486 nm), e-line (546 nm), d-line (588 nm) and C-line (656 nm).

[0012] Some exemplary embodiments may provide an ophthalmic lens system that includes: (A) a lens having an associated power, refractive index, and dispersion and (B) a diffractive optical element. The lens and the diffractive optical element are selected such that when white light passes through the lens system, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

[0013] Some exemplary embodiments may provide an ophthalmic lens system that includes: (A) a lens having an associated power, refractive index, and dispersion and (B) a diffractive optical element. The lens and the diffractive optical element are selected such that when white light passes through the lens system, wavelengths corresponding to red are focused at positions closer to the lens system than wavelengths corresponding to green and blue.

[0014] Some exemplary embodiments may provide an ophthalmic lens system that includes: (A) a lens having an associated power, refractive index, and dispersion and (B) a diffractive optical element. The lens and the diffractive optical element are selected such that when white light passes through the lens system, wavelengths corresponding to the C-line (656 nm) are focused at positions closer to the lens system than wavelengths corresponding to the d-line (588 nm), e-line (546 nm) or the F-line (456 nm).

[0015] In some exemplary embodiments, the lens and the diffractive optical element may be adjoining and in some embodiments, the lens and the diffractive optical element may be spaced apart. In some embodiments, the diffractive element may be positioned within the lens. In some embodiments, the diffractive optical element may be on the front surface of the spectacle lens; while in some other embodiments, the diffractive optical element may be on the back surface of the spectacle lens.

[0016] In some exemplary embodiments, longer wavelengths, such as those corresponding to red light, may be focused at positions located in front of shorter wavelengths, such as those corresponding to blue light.

[0017] In some exemplary embodiments, the lens system may be used to correct vision of an eye and longer wavelengths, such as those corresponding to red light, may be focused at positions located in front of the retina. In some embodiments, wavelengths corresponding to a medium wavelength (such as green light) may be focused at positions located substantially on or close to the retina. In some embodiments, medium wavelengths such as green light may be focused at positions close to or in front of the retina, but further from the ophthalmic lens system than positions where longer wavelengths such as red light are focused. In some embodiments, shorter wavelengths such as blue light may be focused at positions located substantially on or behind the retina.

[0018] In some exemplary embodiments, the ophthalmic lens system may have a reversed longitudinal chromatic aberration that is substantially equal in magnitude but opposite in direction to a longitudinal chromatic aberration of a natural eye or an eye corrected with a conventional lens system (e.g., only the lens portion of the ophthalmic lens system). In some other exemplary embodiments, the ophthalmic lens system may have a reversed longitudinal chromatic aberration that is approximately 2.5, 2.0, 1.5, 1.0, or 0.5 times in magnitude but opposite in direction to the longitudinal chromatic aberration of a natural eye or an eye corrected with a conventional lens system.

[0019] Certain exemplary embodiments provide an ophthalmic lens system that comprises (A) a lens having an associated power, refractive index, and dispersion and (B) a diffractive optical element, such that when light passes through the lens system, the extent of the negative and/or reversed longitudinal chromatic aberration is about 0.5 D (diopters) to about 4 D.

[0020] Certain exemplary embodiments provide an ophthalmic lens system that comprises (A) a lens having an associated power, refractive index, and dispersion and (B) a diffractive optical element, such that when placed on the eye, the extent of the negative and/or reversed longitudinal chromatic aberration is about 0.5 D (diopters) to about 4 D.

[0021] In some exemplary embodiments, the ophthalmic lens system may be used to correct myopia and reduce the progression of myopia. In some other embodiments, the ophthalmic lens system may be used on the eye to prevent it becoming myopic.

[0022] In some embodiments, the ophthalmic lens system that comprises (A) a lens having an associated power, refractive index, and dispersion and (B) a diffractive optical element, may be configured to have a first power for a longer wavelengths such as those corresponding to red light, a second power for a shorter wavelength such as blue light and a third power for a medium wavelength (lying between the longer wavelengths and the shorter wavelengths), such as those corresponding to green light, whereby the first power is substantially more positive (or less negative) than the third power and the second power is substantially more positive (or less negative) than the third power.

[0023] In some embodiments, the ophthalmic lens system that comprises (A) a lens having an associated power, refractive index, and dispersion and (B) a diffractive optical element, may be configured to have a first power for a longer wavelength such as red light and a second power for a shorter wavelength such as blue light whereby the first power may be more positive than the second power and the absolute difference between the first and second power may be greater or substantially greater than the absolute value of the dioptric power equivalent to a longitudinal chromatic aberration of the eye and/or an eye corrected with a conventional lens system.

[0024] In some exemplary embodiments, the lens of the ophthalmic lens system may be a spectacle lens and the diffractive optical element may be a spectacle lens. In some embodiments, the lens of the ophthalmic lens system may be a spectacle lens and the diffractive optical element may be a contact lens. In some embodiments, the lens of the ophthalmic lens system may be a contact lens and the diffractive optical element may be a spectacle lens. In some other embodiments the lens of the ophthalmic lens system may be a wavefront ablation pattern and the diffractive optical element may be a spectacle lens. In some other embodiments, the lens of the ophthalmic lens system may be a corneal inlay and the diffractive optical element may be a spectacle lens. In few other embodiments, the lens of the ophthalmic lens system may be an anterior chamber intra ocular lens, posterior chamber intra ocular lens and the diffractive optical element may be a spectacle lens.

[0025] In some exemplary embodiments, the diffractive optical element may be adapted by the use of optical films and/or directly engraving the diffractive optical element into the optical matrix of the materials of spectacles lens. The optical films would include films that have suitable surface alterations. The optical matrix materials would include suitable materials where the matrix material has been suitably altered.

[0026] In some exemplary embodiments, the ophthalmic lens system may be implemented within only certain visual fields of an overall lens system.

[0027] In some exemplary embodiments, the ophthalmic lens system may be implemented within only certain portions of the aperture of an overall lens system. In some embodiments, the ophthalmic lens system may be incorporated into a plurality of lenslets that are distributed over at least a portion of an overall lens system. In some embodiments, the ophthalmic lens system may be incorporated into a plurality of diffractive zones that are distributed over at least a portion of an overall lens system.

[0028] In some exemplary embodiments, the ophthalmic lens system may be one of a spectacle lens, a contact lens, a corneal onlay or inlay, an intraocular lens or a combination thereof.

[0029] In some exemplary embodiments, the lens may be located in front of (e.g., closer to the light source) the diffractive optical element. In some embodiments, the diffractive optical element may be located in front of (e.g., closer to the light source) the first lens.

[0030] In some exemplary embodiments, the lens may have a negative power, for example a spectacle lens and/or spectacle lens system. In some embodiments, the lens may have a positive power.

[0031] In some embodiments, the ophthalmic lens system may be a single-vision ophthalmic lens.

[0032] In some embodiments, the ophthalmic lens system may incorporate sphero-cylindrical power for vision correction.

[0033] In some embodiments, the ophthalmic lens system may incorporate prisms for vision correction or orthoptics applications.

[0034] In some embodiments, the ophthalmic lens system may incorporate vision correction including higher order aberrations (such as spherical aberrations, coma, astigmatism, curvature of field, distortion).

[0035] In some embodiments, the ophthalmic lens system may be a bifocal or multifocal ophthalmic lens.

[0036] In some embodiments, the ophthalmic lens system may have optical power that varies across the ophthalmic lens.

[0037] Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Aspects of the embodiments described herein may be best understood from the following detailed description when read with the accompanying figures.

[0039] FIG 1 illustrates the spectral sensitivity curves for short (S), medium (M) and long (L) wavelength sensitive photoreceptors of a human retina.

[0040] FIG 2 illustrates the longitudinal chromatic aberration of a human eye. The longitudinal chromatism in Diopters is plotted as a continuous function of visible wavelengths. The figure also shows a table of focal shifts in Diopters for various reference points/wavelengths relevant to the human eye. The focal shift is calculated with respect to the 540 nm wavelength light.

[0041] FIG. 3 is a schematic representation of an ophthalmic lens placed in front of an eye illustrating focal points for wavelengths corresponding to blue, green, and red light in accordance with some embodiments.

[0042] FIG. 4 is a schematic representation of an ophthalmic lens system placed in front of an eye illustrating the reversal of focal point positions that correspond to for blue, green and red wavelengths in accordance with some embodiments.

[0043] FIG 5A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in an emmetropic eye in accordance with some embodiments.

[0044] FIG 5B illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in an emmetropic eye in accordance with some embodiments.

[0045] FIG 5C illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to green 588 nm (d-line) and red 656 nm (C- line) in an emmetropic eye in accordance with some embodiments.

[0046] FIG 6A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about a full blue-red reversal of longitudinal chromatic aberration of approximately 0.25 mm in the image plane (corresponds to approximately 0.8 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA.

[0047] FIG 6B shows additional data related to Figure 6A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0048] FIG. 7A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about a full blue-red reversal of longitudinal chromatic aberration of 0.25 mm in the image plane (corresponds to approximately 0.8 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of Fused Silica.

[0049] FIG 7B shows additional data related to Figure 7A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0050] FIG. 8A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about a full blue-red reversal of longitudinal chromatic aberration of approximately 0.25 mm in the image plane (corresponds to approximately 0.8 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of Polycarbonate.

[0051] FIG 8B shows additional data related to Figure 8A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0052] FIG. 9A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 3 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about a full blue-red reversal of longitudinal chromatic aberration of approximately 0.25 mm in the image plane (corresponds to approximately 0.8 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA.

[0053] FIG 9B shows additional data related to Figure 9A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0054] FIG. 10A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 6 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about a full blue-red reversal of longitudinal chromatic aberration of approximately 0.25 mm in the image plane (corresponds to approximately 0.8 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA.

[0055] FIG 10B shows additional data related to Figure 10A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0056] FIG. 11A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about a half blue-red reversal of longitudinal chromatic aberration of approximately 0.125 mm in the image plane (corresponds to approximately 0.4 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA.

[0057] FIG 11B shows additional data related to Figure 11A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light. [0058] FIG 12A illustrates the longitudinal chromatic aberration for wavelengths corresponding to green (d-line, 588 nm) and red (C-line, 656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about a full red-green reversal of longitudinal chromatic aberration of approximately 0.125 mm in the image plane (corresponds to approximately 0.4 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA.

[0059] FIG 12B shows additional data related to Figure 12A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to green 588 nm (d-line) and red 656 nm (C-line) in accordance with some embodiments.

[0060] FIG. 13A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about half reversal of green (approximately 0.0625 mm) and about full reversal of red (approximately 0.125 mm) in longitudinal chromatic aberration in the image plane (corresponds to approximately 0.4 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA.

[0061] FIG 13B shows additional data related to Figure 13A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0062] FIG. 14A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve about half reversal of green (approximately 0.0625 mm) and more than full reversal of red (approximately 0.14 mm) in longitudinal chromatic aberration in the image plane (corresponds to approximately 0.50 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA. [0063] FIG 14B shows additional data related to Figure 14A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0064] FIG. 15A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (486 nm), green (588 nm) and red (656 nm) light in a 1 Diopter myopic eye which was corrected with a diffractive optical element (DOE) embedded in a spectacle lens to achieve a bout full reversal of green (approximately 0.125 mm) and about double reversal of red (approximately 0.25 mm) in longitudinal chromatic aberration in the image plane (corresponds to approximately 1.2 Diopters) in accordance with some embodiments. The material of the ophthalmic lens system is made of PMMA.

[0065] FIG 15B shows additional data related to Figure 15A. It illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light.

[0066] FIG 16 illustrates various different types of diffractive optical elements (Kinoform, 4-step, 8-step and binary) that are used in conjunction with a traditional spectacle lens.

DETAILED DESCRIPTION

[0067] The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

[0068] The following description is provided in relation to several embodiments that may share common characteristics and features. It is to be understood that one or more features of one embodiment may be combined with one or more features of other embodiments. In addition, a single feature or combination of features in certain of the embodiments may constitute additional embodiments. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the disclosed embodiments and variations of those embodiments.

[0069] The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.

[0070] As used herein, shorter wavelengths mean a wavelength of between about 380 nm to about 425 nm, between about 380 nm to about 480 nm, between about 420 nm to about 480 nm or between about 400 nm and about 490 nm. In certain embodiments, the shorter wavelength is (or about) 400 nm, 450 nm, 475 nm, 486 nm, or 486 nm.

[0071] As used herein, longer wavelengths means a wavelength of between about 575 nm to about 780 nm, 600 nm to about 700 nm, about 555 nm to about 640 nm, about 535 nm and about 585 nm or between about 560 nm and about 650 nm. In certain embodiments, the longer wavelength is 589 nm, or about 589 nm, 656 nm, or about 656 nm. As discussed above, exemplary embodiments are directed to the involvement of longitudinal chromatic aberrations (LCA) in the development (e.g., growth) of the eye progressing towards myopia and/or decoding the direction of eye growth in a progressing myopic eye. Longitudinal chromatic aberration is caused by a property (dispersion) that exists in optical materials. As a result of dispersion, the refractive index of optical materials may be different for different wavelengths of light, causing different colors/wavelengths of light to focus at different points (e.g., convergence points). The varying refractive indices of the lens material with the wavelength of incident light cause a shorter wavelength of light (e.g., blue light) to have a convergence point that is in front of a longer (e.g., medium) wavelength of light (e.g., green light) which in turn have a convergence point that is in front of an even longer wavelength of light (e.g., red light). [0072] As used herein, "reverse", "invert", "interchange", or "opposite" when referring to longitudinal chromatic aberration means changing the sign of the longitudinal chromatic aberration. For example, for an eye with positive longitudinal chromatic aberration, an ophthalmic lens and/or ophthalmic lens system that reverses, inverts or interchanges the longitudinal chromatic aberration of the eye will, when worn, provide for the eye, a negative longitudinal chromatic aberration.

[0073] As used herein, "negative longitudinal chromatic aberration" means a longitudinal chromatic aberration whereby the focal length of an optical system (e.g., a lens, a lens system, an eye, or an eye wearing a lens and/or lens system) for a shorter wavelength is more positive than the focal length for a longer wavelength. Alternatively and equivalently, when expressed in dioptric terms, "negative longitudinal chromatic aberration" means a longitudinal chromatic aberration whereby the power of an optical system for a longer wavelength is more positive than that for a shorter wavelength.

[0074] In the context of vision, the human eye may be more sensitive to wavelengths corresponding to green light over other colors of light with shorter or longer wavelengths. As a result, ophthalmic lens systems (e.g., spectacles, contact lenses, onlays, inlays, intra ocular lenses, etc.) may be designed such that the convergence point for wavelengths corresponding to green light is located on (or substantially close to) the retina of the eye to produce an image that is in focus (e.g., clear) from the perspective of the individual. As a result, the convergence point for wavelengths corresponding to blue light may be in front of the retina (i.e., relatively myopic) and the convergence point for the wavelengths corresponding to red light may be behind the retina.

[0075] One or more of the following advantages may be found in one or more of the devices, methods and/or systems described herein:

A. The ophthalmic lens and/or ophthalmic lens system may provide a stop signal to reduce or stop eye growth (or the state of refractive error) to the wearer's eye irrespective (or substantially irrespective) of the direction of gaze of the wearer's eye relative to the center of the ophthalmic lens and/or the ophthalmic lens system. B. For effective myopia control, the wearer of the spectacle lens and/or spectacle lens system may not have to look through a specific portion of the spectacle lens and/or spectacle lens system.

C. The spectacle lens and/or spectacle lens system may cosmetically appear like a typical spectacle lens and may not suffer from the potential dislike shown by certain wearers (e.g., certain bifocal spectacles).

D. The ability to alter the longitudinal chromatic aberration using diffractive optical elements in conjunction with a spectacle lens.

[0076] Certain embodiments of the present disclosure are directed to devices, methods and/or systems that are capable of providing a spectacle lens and/or spectacle lens system that provides a stop signal to the progressing eye for at least a portion, or at least a substantial portion, of the viewing angles of the spectacle lens and/or spectacle lens system that the child and/or viewer is using. As used herein, at least a portion means at least 50%, 60%, 70%, 80% or 90% of the possible viewing angles when the spectacle lens and/or spectacle lens system is being worn by the child and/or viewer. As used herein, at least a substantial portion means at least 80%, 90%, 95%, 98% or 99% of the possible viewing angles when the spectacle lens and/or spectacle lens system is being worn by the child and/or viewer.

[0077] The diffractive optical element disclosed herein may vary substantially in their properties. In certain embodiments, the diffractive optical element may be manufactured in sheets that may be made up of more than 1 layer, for example 2, 3, 4 or 5 layers. In certain embodiments, the diffractive optical element may be manufactured in sheets that may be made up of at least 1, 2, 3, 4 or 5 layers. The sheets may then be cut or configured to properly fit or work in conjunction with a spectacle lens blank. The diffractive optical element may be located on the anterior surface of the spectacle lens, the posterior surface of the spectacle lens, embedded in the spectacle lens matrix, in the first layer of the spectacle lens, in the second layer of the spectacle lens, in the third layer of the spectacle lens, in the fourth layer of the spectacle lens, in the fifth layer of the spectacle lens or combinations thereof. The diffractive optical element may be applied or adhered to a spectacle lens in order to work in conjunction with the spectacle lens in a number of ways including, but not limited to, adhesives (thermal or chemical) or mechanical.

[0078] In exemplary embodiments, the diffractive optical element may be circular, semi-circular, non-circular, oval, rectangular, hexagonal or square in shape.

[0079] In certain embodiments, the shape of the optical phase resulting due to the diffractive optical element may be described by one or more of the following: a sphere, an asphere, extended odd polynomial, extended even polynomial, conic, biconic, superconic, toric surface or Zernike polynomials. The surface of the diffractive optical element may be described as a binary-step, 2-step, 4-step, 8-step, kinoform or a blazed grating.

[0080] In certain other embodiments, fabrication of the diffractive optical element may be through construction of a continuous surface relief structure over the refractive spectacle lens using laser direct writing techniques. Fermat's principles known to the person skilled in the art, with thin lens approximation, may be used to design, fabricate, and characterize diffractive optical elements with continuous deep surface relief structures using parallel laser direct writing on thin films which could be used in conjunction with a conventional spectacle lens.

[0081] Figure 3 is a schematic representation of an ophthalmic lens used in conjunction with a human eye. The incoming bundle of rays constituting polychromatic light converge to form distinct focal points for wavelengths corresponding to blue, green, and red wavelengths. As illustrated in Figure 3, incident light of various wavelengths enters a lens 10. The lens 10 is an ophthalmic lens (e.g., a spectacle lens). The light entering the lens 10 may include wavelengths corresponding to green light, wavelengths corresponding to blue light and wavelengths corresponding to red light. As illustrated, the different wavelengths of light may have different convergence points. For example, as a result of dispersion, the shorter wavelengths of light [e.g., blue light (b)] may have a convergence point closer to the lens. Longer wavelengths of light [e.g., green light (g)] may have a convergence point further away from the lens. Even longer wavelengths of light [e.g., red light (r)] may have a convergence point even further away from the lens 10. This difference in focal length results in longitudinal chromatic aberration which causes a spread of the convergence points. While the distances between the convergence points may change, the relative position of the shorter and longer wavelength convergence points typically does not change as a function of optical power or refractive index of the lens 10.

[0082] In Figure 3, a convergence point may be located at or near the retina of the eye so that wavelengths corresponding to green light are focused at or near the retina. This may be true for corrected eyes, eyes that do not require correction (e.g., emmetropic eyes), and/or lenses designed to correct vision. In eyes that do not require correction, the shorter wavelengths of light may be relatively more myopically focused than the medium or longer wavelengths of light. The longer wavelengths of light (e.g., red light) focused at convergence point may be located behind the retina and therefore may be more hyperopic. In some embodiments, the hyperopic defocus of the longer wavelength light (e.g., red light) may contribute to or stimulate the development and/or progression of myopia.

[0083] For the model human eye in Figure 3, the longitudinal chromatic aberration was calculated for 486 nm (blue), 588 nm (green), and 656 nm (red) which correspond to the standard Fraunhofer lines (i.e., the F-, d-, and C- lines). The longitudinal chromatic aberration was converted to diopters using a paraxial surface. As illustrated in longitudinal chromatic aberration graph of Figure 3, the blue light (b) is focused in front of the retina (e.g., about 0.16 mm in front of the retina), the green light (g) is focused substantially on the retina, and the red light (r) is focused behind the retina (e.g., approximately 0.08 mm behind the retina). The dioptric longitudinal chromatic aberration of this eye over the standard Fraunhofer lines is about 0.83 D, which lies within the range of published measurements of human longitudinal chromatic aberration.

[0084] Accordingly, in some embodiments, it may be desirable to move the convergence point for longer wavelengths forward. In some embodiments, an ophthalmic lens system may be configured such that the longer wavelengths of light (e.g., red light) are relatively more myopically focused than the shorter wavelengths (e.g., blue lights). In some embodiments, these types of systems or devices may be referred to as providing reversed longitudinal chromatic aberration as the relative positions of the shorter and longer wavelength points of convergence are opposite that of conventional systems or devices.

[0085] In some embodiments, the optical element may be a lens (e.g., similar to or identical to the lens 10 in Figure 3) and the element may be a diffractive surface. In some embodiments, the lens may be a lens doublet as described in U.S. Provisional Application No. 62/463,942. The diffractive surface 20 may be positioned such that it adjoins the outer surface of the lens 21, as illustrated in Figure 4. Alternatively, the lens 20 and diffractive surface 21 may be spaced apart from one another. In some embodiments, the gap between the lens 20 and the diffractive surface 21 may include some material.

[0086] Figure 4 is a schematic representation of an ophthalmic lens system used in conjunction with a human eye, in accordance with embodiments. The incoming bundle of rays constituting polychromatic light converge to form distinct focal points for wavelengths corresponding to blue, green and red wavelengths. As illustrated, the focal point positions that correspond to blue, green and red wavelengths are reversed in order (as compared to Figure 3).

[0087] In some embodiments, the lens 21 and the diffractive surface 20 may each have respective dispersion and refractive index characteristics and may be selected so that the combination of the different refractive indices for different wavelengths and their different optical powers result in a reversed longitudinal chromatic aberration. The shorter wavelengths of light (e.g., blue light) may have a convergence point that is further away from the lens than longer wavelengths of light (e.g., green light) that have a convergence point. Furthermore, even longer wavelengths of light (e.g., red light) may have a convergence point that is closer to the lens than both the wavelengths corresponding to blue light and wavelengths corresponding to green light.

[0088] This reversal in the longitudinal chromatic aberration causes the relative position of the shorter and longer wavelength convergence points to switch. As a result, convergence point may be located at or near the retina of the eye so that wavelengths corresponding to green light are focused at or near the retina while the longer wavelengths of light (e.g., red light) focused at convergence points may be located in front of the retina and therefore may be more myopic. Shorter wavelengths of light (e.g., blue light) focused at convergence points may be located behind the retina and therefore may be more hyperopic.

[0089] In some embodiments, the reversed longitudinal chromatic aberration may be equal (e.g., substantially equal) in magnitude but opposite in direction to the longitudinal chromatic aberration of a natural eye or a natural eye corrected with a conventional lens system. In some embodiments, the reversed longitudinal chromatic aberration for at least two selected wavelengths may be equal (e.g., substantially equal) in magnitude but opposite in direction to the longitudinal chromatic aberration for the at least two selected wavelengths of a natural eye or a natural eye corrected with a conventional lens. As used herein, the term equal means that the reversed longitudinal chromatic aberration magnitude is within at least 10%, 8%, 6%, 4%, 2% or 1% of the magnitude of the longitudinal chromatic aberration. As used herein, the term substantially equal means that the reversed longitudinal chromatic aberration magnitude is within at least 30%, 25%, 20% or 10% of the magnitude of the longitudinal chromatic aberration. Accordingly, by combining the lens 21 and diffractive surface 20 with different characteristics, it may be possible to achieve an optical effect in which the longer wavelength focus will be positioned relatively more myopically than the shorter wavelength focus. In some embodiments, it is thought that this arrangement of an ophthalmic lens system may reduce or eliminate the progression of myopia.

[0090] Figure 5A illustrates the longitudinal chromatic aberration in an emmetropic eye that is progressing towards myopia and Figures 6A to 15A illustrate the longitudinal chromatic aberration in myopic eyes (-1 D, -3 D and -6 D) when corrected with a diffractive optical element used in conjunction with a single vision spectacle lens. [0091] The prescription parameters of the theoretical eye model used for simulation of the results in this exemplary embodiment are provided in Table 1. All modelling was done for a 6 mm pupil and the refractive state was determined at the monochromatic wavelength of 588 nm.

[0092] For all simulations the parameters were kept the same, except the vitreous chamber depth, which depending on the refractive state of the model eye was altered. For the emmetropic eye the vitreous chamber depth was set to 16.527 mm (Surface No 8a in Table 1). For examples 1, 2, 3 and 6 to 10, the vitreous chamber depth was set to 16.679 mm (Surface No 8b in Table 1), which results in a 1 Diopter myopic eye. For examples 4 and 5 the vitreous chamber depth was set to 17.438 mm (Surface No 8c in Table 1) and 18.686 mm (Surface No 8d in Table 1), which result in a 3 and a 6 Diopter myopic eye, respectively.

[0093] Table 1: Parameter values of the myopic theoretical model eyes.

Table 1 [0094] The parameter values described in Table 1 are by no means imperative to demonstrate the effect being described. This is just one of the many models that may be used for simulation purposes. For example, in other exemplary embodiments, model eyes like Liou-Brennan, Escudero-Navarro, Atchison, etc. may be used instead of the above model eye. One may also alter the parameters of the cornea, lens, retina, ocular media, or combinations thereof, to aid simulation.

[0095] Figure 5A illustrates the longitudinal chromatic aberration for wavelengths corresponding to blue (F-line, 486 nm), green (d-line, 588 nm) and red (C-line, 656 nm) light in an emmetropic eye that is progressing towards myopia. Figure 5B illustrates the Polychromatic Modulation Transfer Function (MTF) calculated for wavelengths corresponding approximately to 486 nm (F-line), 588 nm (d-line) to 656 nm (C-line) in an emmetropic eye. As can be seen the MTF is plotted as a function of angular frequency with an upper limit of 3.4 cycles per milli-radians. This frequency corresponds to a spatial frequency of 60 cycles per degree, which in turn corresponds to the cut-off frequency of the visual system's ability to resolve fine details. Figure 5C illustrates the Polychromatic Modulation Transfer Function calculated for wavelengths corresponding to 588 nm (d- line) and 656 nm (C-line) in an emmetropic eye. In other exemplary embodiments relating to Figures 5A, 5B, 5C, one or more of the following may vary: the wavelength of choice for MTF calculations may be a suitable wavelength in the visible spectrum (approximately between 400 nm and 760 nm), the upper limit of the angular frequency selected between the range of 1 cycle per milli-radian and 4 cycles per milli-radian or combinations thereof. EXAMPLES

Example 1: Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of PMMA (Refractive error Rx: -1 D)

[0096] This exemplary embodiment describes a diffractive optical element used in conjunction with a single vision spectacle lens to correct a myopic eye or an eye progressing towards myopia. Binary optics simulations were used to model the effects of the diffractive optical element + single vision lens on the longitudinal chromatic aberration of the corrected eye. In this example, the diffractive optical element was designed on the front surface of the spectacle lens. The sag of the front surface of the spectacle lens was defined using an even aspheric surface. The even aspheric surface is described by a polynomial expansion of the deviation from an aspheric surface, the surface sag, z, is given by:

Where, 'c' is the curvature (the reciprocal of radius of curvature);

V is the radial co-ordinate in lens units defined as (x² + y²)^{1 2};

'k' is the conic constant (Conic constant <-l hyperbola; -1 for parabola; between - 1 and 0 for ellipse; 0 for spheres and >0 for oblate ellipsoids); and

'α to 'α8' are coefficients of the even polynomial expansion.

[0097] The front surface of the spectacle lens also includes binary optics phase profile. Binary optics are similar to diffraction gratings, where small groves on the surface impart a change in the phase of the wavefront passing through the surface. Instead of directly modelling the wavelength-scale groves, this example uses the property of local phase advance/delay to change the direction of propagation of the ray. The binary optic surface adds phase (φ) to the traced rays, according to the following polynomial ex ansion:

ΐ = ί

Where, M is the diffraction order

N is the total number of coefficients

A, is the coefficient of the 2i^th power of p

p is the normalized radial aperture co-ordinate

In this example, the back surface is defined as a simple aspheric surface, whose sag, z, is defined by:

Where, 'c' is the curvature (the reciprocal of radius of curvature); V is the radial co-ordinate in lens units defined as (x² + y²)^{1 2}; and 'k' is the conic constant (Conic constant <-l hyperbola; -1 for parabola; between - 1 and 0 for ellipse; 0 for spheres and >0 for oblate ellipsoids).

[0098] In this example, see Figure 6A, according to certain exemplary embodiments, a -1 D myopic eye was corrected with a spectacle lens system designed with a diffractive optical element. The material of the ophthalmic lens system is made of PMMA. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used oil = 2.142xl0^~3. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A3 are - 2973.906, -825.466 and 6322.473, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463. This spectacle lens system when applied to the eye results in approximately a complete reversal of the longitudinal chromatic aberration for blue (F-line, 486 nm) and red (C-line, 656 nm) wavelengths, which is approximately 0.25 mm in the image plane (that corresponds to approximately 0.8 Diopters, seen in Figure 6A). Longitudinal chromatic aberration was calculated over a 6 mm pupil diameter.

[0099] Figure 6B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 nm (F-line), 588 nm (d-line) and 656 nm (C-line) nm. As can be seen, the area under the MTF is slightly lower than the MTF in the emmetropic eye (Figure 5B), indicating marginally reduced optical performance.

Example 2: Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of Fused Silica (Refractive error Rx: -1 D)

[00100] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1, however the diffractive optical element in this example is made out of Fused silica. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 1.637xl0^"3. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A3 are -3005.269, -828.580 and 6341.569, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463. This spectacle lens system when applied to the eye results in approximately a complete reversal of the longitudinal chromatic aberration for blue (F- line, 486 nm) and red (C-line, 656 nm) wavelengths, which is approximately 0.25 mm in the image plane (that corresponds to approximately 0.8 Diopters, seen in Figure 7A). Longitudinal chromatic aberration was calculated over a 6 mm pupil diameter.

[00101] Figure 7B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 nm (F-line), 588 nm (d-line) and 656 nm (C-line) nm. As can be seen the area under the MTF is slightly lower than the MTF of the emmetropic eye (Figure 5B), indicating slight reduction in optical performance.

Example 3: Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of polycarbonate (Refractive error Rx: -ID)

[00102] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1; however the diffractive optical element in this example is made out of polycarbonate. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 3.381xl0 ³. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A3 are -2807.255, -817.592 and 6272.408, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463. This spectacle lens system when applied to the eye results in approximately a complete reversal of the longitudinal chromatic aberration for blue (F- line, 486 nm) and red (C-line, 656 nm) wavelengths, which is approximately 0.25 mm in the image plane (that corresponds to approximately 0.80 Diopters, seen in Figure 8A). Longitudinal chromatic aberration was calculated over a 6 mm pupil diameter. [00103] Figure 8B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 nm (F-line), 588 nm (d-line) and 656 nm (C-line) nm. As can be seen the area under the MTF is slightly lower than the MTF of the emmetropic eye (Figure 5B), indicating slight reduction in optical performance.

Example 4: Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of PMMA (Refractive error Rx: -3 D)

[00104] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1; however the diffractive optical element + single vision lens system is configured to correct a -3 D myopic eye. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 9.765xl0^~5. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A3 are -2995.202, -901.303 and 7964.636, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463. This spectacle lens system when applied to the eye results in approximately a complete reversal of the longitudinal chromatic aberration for blue (F-line, 486 nm) and red (C-line, 656 nm) wavelengths, which is approximately 0.25 mm in the image plane (that corresponds to approximately 0.8 Diopters, seen in Figure 9A). Longitudinal chromatic aberration was calculated over a 6 mm pupil diameter.

[00105] Figure 9B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 nm (F-line), 588 nm (d-line) and 656 nm (C-line) nm. As can be seen the area under the MTF is slightly lower than the MTF of the emmetropic eye (Figure 5B), indicating slight reduction in optical performance.

Example 5: Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of PMMA (Refractive error Rx: -6D)

[00106] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1; however the diffractive optical element + single vision lens system is configured to correct a -6D myopic eye. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 9.560xl0^~4. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A3 are -3008.338, -982.066 and 11021.400, respectively. The radius of the back surface of the spectacle lens is 40 mm with a conic constant of -1.463. This spectacle lens system when applied to the eye results in a complete reversal of the longitudinal chromatic aberration for blue (F-line, 486 nm) and red (C-line, 656 nm) wavelengths, which is approximately 0.250 mm in the image plane (that corresponds to approximately 0.80 Diopters, seen in Figure 10A). Longitudinal chromatic aberration was calculated over a 6 mm pupil diameter.

[00107] Figure 10B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 nm (F-line), 588 nm (d-line) and 656 nm (C-line) nm. As can be seen the area under the MTF is slightly lower than the MTF of the emmetropic eye (Figure 5B), indicating slight reduction in optical performance.

Example 6: Semi-Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of PMMA (Refractive error Rx: -ID)

[00108] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1. However, the myopic eye was corrected with a diffractive optical element in conjunction with the single vision lens system that was configured to correct a -1 D myopic eye and introduce approximately about half of the reversal of longitudinal chromatic aberration observed in Example 1; approximately 0.125 mm in the image plane (which corresponds to approximately 0.4 Diopters) for blue (F-line, 486 nm) and red (C-line, 656 nm) wavelengths, seen in Figure 11A. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 3.559xl0^~3. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A₃ are -2224.084, -849.149 and 6484.631, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463.

[00109] Figure 11B illustrates the Polychromatic Modulation Transfer Function

(MTF) for wavelengths 486 nm (F-line), 588 nm (d-line) and 656 nm (C-line) nm. As can be seen the area under the MTF is lower than the MTF in the emmetropic eye (Figure 5B) but greater when compared to examples 1 to 5 (Figures 6B to 10B), where the DOE was designed for full blue-red reversal of longitudinal chromatic aberration.

Example 7: Reversal of green and red lines using diffractive optical element on a spectacle lens made of PMMA (Refractive error Rx: -ID)

[00110] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1. However, the myopic eye was corrected with a diffractive optical element in conjunction with the single vision lens system that was configured to correct a -1 D myopic eye and reverse longitudinal chromatic aberration corresponding to green (d-line, 588 nm) and red (C-line, 656 nm), seen in Figure 12A. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 1.635xl0^~3. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A₃ are -3004.809, -799.775 and 6127.888, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463.

[00111] Figure 12B illustrates the Polychromatic Modulation Transfer Function

(MTF) for wavelengths 588 (d-line) and 656 (C-line) nm. As can be seen the area under the MTF is similar when compared to the MTF in the emmetropic eye (Figure 5C).

Example 8: Partial-Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of PMMA (Refractive error Rx: -1 D)

[00112] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1. However, the myopic eye was corrected with a diffractive optical element in conjunction with the single vision lens system that was configured to correct a -1 D myopic eye, wherein the blue (F-line, 486 nm) was in focus, the green line (d-line, 588 nm) was approximately 0.052 mm in front of the blue line and the red (C-line, 656 nm) was approximately 0.125 mm in front of the blue line, the reversal of the longitudinal chromatic aberration in the image plane corresponds to approximately 0.4 Diopters, as seen in Figure 13A. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used oil = 3.907xl0^~3. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A3 are -2136.660, -1068.697 and 8834.854, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463.

[00113] Figure 13B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 (F-line), 588 (d-line) and 656 (C-line) nm. As can be seen the area under the MTF is lower than the MTF in the emmetropic eye (Figure 5B) but greater when compared to examples 1 to 5 (Figures 6B to 10B), where the DOE was designed for full blue-red reversal of longitudinal chromatic aberration.

Example 9: Partial-Reversal of longitudinal chromatic aberration using diffractive optical element on a spectacle lens made of PMMA (Refractive error Rx: -1 D)

[00114] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1. However, the myopic eye was corrected with a diffractive optical element in conjunction with the single vision lens system that was configured to correct a -1 D myopic eye, where n the blue (F-line, 486 nm) was in focus, the green line (d-line, 588 nm) was approximately 0.0625 mm in front of the blue line and the red (C-line, 656 nm) was approximately 0.125 mm in front of the blue line, the reversal of the longitudinal chromatic aberration in the image plane corresponds to approximately 0.6 Diopters, as seen in Figure 14A. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 3.692xl0^"3. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A3 are -2268.385, -869.442 and 6683.043, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463.

[00115] Figure 14B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 (F-line), 588 (d-line) to 656 (C-line) nm. As can be seen the area under the MTF is lower than the MTF in the emmetropic eye (Figure 5B) but greater when compared to examples 1 to 5 (Figures 6B to 10B), where the DOE was designed for full blue-red reversal of longitudinal chromatic aberration.

Example 10: Partial Reversal DOE on PMMA -1 D Spectacle Lens

[00116] This exemplary embodiment describes the use of a diffractive optical element used in conjunction with a single vision spectacle lens, similar to Example 1. However, the myopic eye was corrected with a diffractive optical element in conjunction with the single vision lens system was configured to correct a -1 D myopic eye, wherein the blue (F-line, 486 nm) was in focus, the green line (d-line, 588 nm) was approximately 0.125 mm in front of the blue line and the red (C-line, 656 nm) was approximately 0.25 mm in front of the blue line, the reversal of the longitudinal chromatic aberration in the image plane corresponds to approximately 1.2 Diopters, as seen in Figure 15A. The total lens diameter of this example was 50 mm, however the diffractive optical element was defined over 20 mm diameter. The curvature of anterior surface of the spectacle lens was Piano (i.e. radius = infinity); one coefficient of the even asphere expansion was used al = 2.620xl0 ³. In addition, the binary optical phase was defined over the 20 mm diameter using 3 coefficients of the expansion: Ai, A₂ and A₃ are -2953.778, -835.230 and 6119.479, respectively. The radius of the back surface of the spectacle lens is 60 mm with a conic constant of -1.463. [00117] Figure 15B illustrates the Polychromatic Modulation Transfer Function (MTF) for wavelengths 486 (F-line), 588 (d-line) to 656 (C-line) nm. As can be seen the area under the MTF is lower than the MTF in the emmetropic eye (Figure 5B).

[00118] In exemplary embodiments, differing types of diffractive optical elements may be utilized. For example, one type of diffractive optical element is an element with grooves (e.g., concentric rings or zones of grooves). In some embodiments, the grooves may be binary grooves or pillars. That is the diffractive element essentially has alternating raised and recessed surfaces. In some embodiments, the grooves may not be binary but may instead by stepped (e.g., 4 step or 8 step) grooves. In these cases, the grooves form more of a "staircase" pattern with e.g., 4 or 8 levels. In some embodiments, the grooves may be blazed grooves that form more of a continuous transition from between the grooves instead of discrete steps. In some embodiments, the grooves may be kinoform grooves which are similar to the blazed grooves except the transition between grooves is more arcuate than linear. Figure 16 illustrates various different types of diffractive optical elements (Kinoform, 4-step, 8-step and binary) that are used in conjunction with a traditional spectacle lens.

[00119] Certain embodiments may be modified such that the convergence point was slightly in front of the retina. In some embodiments, this may introduce a myopic defocus.

[00120] In some embodiments, the lens may be implemented as a single-vision ophthalmic lens (e.g., spectacle lenses, contact lens, onlay, inlay and/or intraocular lenses).

[00121] In some embodiments, the lenses with reversed longitudinal chromatic aberration may be implemented within certain visual fields. For example, it may be implemented in a combination of a central 15 degrees of the field of view by using a round-segment that is centered to the visual axis; or a peripheral field beginning from 20 degrees; or dropped segments similar to the outline shape of bifocal spectacle lenses. I n some other embodiments, the lenses with reversed longitudinal chromatic aberration may be implemented with oval or tilted segments to account for downward gaze while viewing near targets through the spectacle lens system.

[00122] In some embodiments, the lenses with reversed longitudinal chromatic aberration may be implemented within a portion or portions of the aperture. For example, it may be implemented within the central 50% area of the aperture, or the central 30% of the aperture, or the central 35% of the aperture, or the central 40% of the aperture, or the central 45% of the aperture, or the central 55% of the aperture, or the central 60% of the aperture, or the central 65% of the aperture, or the central 70% of the aperture, or implemented within the peripheral 50% area of the aperture, or the peripheral 60% area of the aperture, or the peripheral 55% area of the aperture, or the peripheral 45% area of the aperture, or the peripheral 40% area of the aperture, or the peripheral 35% area of the aperture, or the peripheral 30% area of the aperture. In some embodiments, lenslets and/or microlenslet arrays implementing multiple lenslets with reverse longitudinal chromatic aberrations may be distributed over or in the bulk of a lens (see, e.g., U.S. Provisional Application No. US 62/412,507, filed on October 25, 2016 and International Application No. PCT/AU2017/051173, filed on October 25, 2017, both of which are herein incorporated by reference in their entirety).

[00123] In some embodiments, Fresnel type optics may be utilized to reduce overall lens thickness and/or weight. In some elements, the Fresnel may be refractive or diffractive. In some embodiments, the segment lens or lenslets and/or microlenslet arrays providing the reverse longitudinal chromatic aberrations may have a different optical power from the portion of the lens that does not provide a reverse longitudinal chromatic aberration. For example, the segment lens may be more positive in power to introduce relative myopic defocus over those parts of the visual field.

[00124] In some embodiments, the optical power over the segment lens or lenslets and/or microlenslet arrays providing the reverse longitudinal chromatic aberration may be the same as the optical power over the portion of the lens that does not provide reverse longitudinal chromatic aberration.

[00125] In some embodiments, the reverse longitudinal chromatic aberration may or may not take into consideration the longitudinal chromatic aberration of the natural/physiological/existing structure of the eye.

[00126] In other exemplary embodiments, the size of the diffractive optical element is at least ½, ¼ or l/8^th of the total diameter of the spectacle lens.

[00127] The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Methods of testing

[00128] Exemplary embodiments may be tested by evaluating reversal of longitudinal chromatic aberration on a physical model eye or by use of a commercially available PMTF (power and MTF) instrument with a simplified model eye or in vivo when placed in front of the human eye.

[00129] Exemplary embodiments may be tested by evaluating on a physical model eye. For example, a physical model eye (Brien Holden Vision Institute Model Eye, which may also be referred to as "MESH") may be used for conducting in vitro, physical measurement of optical performance of ophthalmic lens system that mimics the environment of the typical human eye. This physical model eye has been published in a peer-reviewed journal article (Bakaraju, Ehrmann, Falk, Ho, Papas "Physical human model eye and methods of its use to analyse optical performance of soft contact lenses" Optics Express Volume 18, No. 16, August 2, 2010, Pages 16868-16882, which is herein incorporated by reference in its entirety). Such a physical model eye may be used to measure longitudinal chromatic aberration of an eye with, and without, correction. To facilitate this, the retinal position of the physical model eye may be adjusted until best focus is achieved for various wavelengths, for example: 450 nm, 500 nm, 550 nm, 600 nm and 650 nm.

[00130] Measurement of the longitudinal chromatic aberration of the ophthalmic lens system may also be achieved by using a commercially available PMTF (Power and MTF) instrument (Lambda-X, Nivelles, Belgium) and a simplified model eye that complies with ISO11979-2:2014 standards. Using the auto-adjust mode the retina positions for different wavelengths, such as 480 nm, 546 nm and 633 nm, may be determined and longitudinal chromatic aberration may be plotted.

[00131] Measurement of the reversal of longitudinal chromatic aberration of the exemplary ophthalmic lens system may also be demonstrated in vivo in non-color vision deficient participants. This can be done by correcting the eyes for distance vision (e.g. subjective refraction with a phoropter) first using a standard high contrast vision chart. At the same distance, monochromatic letters in the primary colors red, green and blue may then be presented on a black background, to simulate long, medium and short wavelengths. When placing a +1 D fogging lens in front of the participant's eye, the foci for the wavelengths will then move in front of the retina. Fogging is a technique familiar to and used by eye care practitioners to eliminate a patient's tendency to accommodate (or focus to near) during an eye test. As fogging is reduced with minus lenses, participants may identify the lens (i.e. fogging lens + minus lens) that achieved best focus first for each letter. To assess reversal of longitudinal chromatic aberrations, this procedure may be done with the exemplary ophthalmic lens system placed in front of the eye and without (control).

[00132] In the control case, i.e., without the exemplary ophthalmic system, and thus no reversal of longitudinal chromatic aberration, it would be expected that red is in focus first (i.e. least amount of minus required to achieve best focus), followed by green, then blue. This is due to the fogging procedure placing the three foci for the wavelengths in front of the retina and the red focus being positioned furthest towards the retina (i.e. more posterior relative to green and blue foci). As fogging is reduced, the three foci move progressively posteriorly towards the retina. Given the eye's positive longitudinal chromatic aberration, the red focus would reach the retina first and therefore be perceived and reported by the wearer as being clear first. With the exemplary ophthalmic system, the opposite would be expected, i.e., greatest amount of minus is required to achieve best focus for red, as longitudinal chromatic aberration is reversed by this lens system.

[00133] In some embodiments, the medium wavelength may be selected set as one of the green wavelengths such as that corresponding to the Fraunhofer D (sodium) line (about 589 nm) or Helium d line (about 588 nm), while the shorter and longer wavelengths may be set to wavelengths such as those corresponding to the Fraunhofer F line (about 486 nm) and Fraunhofer C line (about 656 nm) lines respectively. However, for certain applications, other wavelengths and their corresponding refractive indices may be used. For example, the medium wavelength may be selected to be the wavelength corresponding to the mercury e line (about 546 nm).

[00134] The Fraunhofer symbols (e.g. d, C, F, etc.) is a recognized set of labels representing specific wavelengths.

[00135] As used herein in this disclosure, the term reversal refers to a situation, wherein white light passing through the ophthalmic lens system or a diffractive optical element, the longer wavelengths are focused at positions substantially closer to the lens system than the shorter wavelengths. For example, the F-line and C-line, passing through the ophthalmic lens system or a diffractive optical element, the longer wavelengths (C- line) are focused at positions substantially closer to the lens system than the shorter wavelengths (F-line).

[00136] As used herein in this disclosure, the term stop signal refers to a situation achieved via reversal of longitudinal chromatic aberrations wherein the L cones experience myopically defocused images relative to the M cones and/or S cones, which provide a stop signal to a myopic eye or an eye that is progressing towards myopia. The term stop signal also refers to a situation achieved via reversal of longitudinal chromatic aberrations wherein the L cones experience a different growth signal relative to the M cones and/or S cones, which provide a stop signal to a myopic eye or an eye that is progressing towards myopia.

[00137] As used herein in this disclosure, conventional lens, or conventional ophthalmic lens, means a lens that corrects refractive error of the wearer but that does not have the function of deliberately controlling, substantially controlling, reversing or substantially reversing longitudinal chromatic aberrations of the corrected eye for specific wavelengths, for example, at 486 nm, 546 nm, 588 nm, 589 nm and/or 656 nm.

[00138] For some embodiments, design of the ophthalmic lens system may be facilitated by optical ray-tracing (e.g. Zemax, OSLO, and CodeV), fast physical optics software (Virtual lab/Light Trans) or custom lens design software. With such software, it may be possible to tailor/design the ophthalmic lens system to perform differently at specific wavelengths (for example by using appropriate groove depth of the diffractive optical element used in conjunction with conventional spectacle lens).

[00139] With the presence of some individual variability in the reversed longitudinal chromatic aberration response, different approaches may be taken for design of such ophthalmic lens systems. For example, the longitudinal chromatic aberration of an individual may be measured using a technique described above and the ophthalmic lens system designed to introduce reversed longitudinal chromatic aberration for that specific eye. Alternatively, the longitudinal chromatic aberration of a population, or sub-population (e.g. children) may be obtained by clinical studies or from published data and used as the basis for design of ophthalmic lens systems that effects reversed longitudinal chromatic aberration for eyes wearing the lens or lens system.

[00140] The actual amount of reversal may vary depending on the specific application and intended treatment for myopia. For example, the amount of reversal may be equal and opposite to the longitudinal chromatic aberration of the eye. Or a greater amount may be effected such as 1.5x the longitudinal chromatic aberration of the eye and reversed. Greater amounts may also be of benefit.

[00141] Alternatively, there may be benefit in terms of reduction of myopia progression, or delaying of onset of myopia development, by effecting a reversed longitudinal chromatic aberration to an amount that is a portion of the longitudinal chromatic aberration of the natural eye or eye wearing conventional ophthalmic lens systems.

[00142] For some embodiments, the longitudinal chromatic aberration effected for an eye (that is, the resultant ocular longitudinal chromatic aberration when the ophthalmic lens system is used with the eye) may be a negative longitudinal chromatic aberration.

[00143] For some embodiments, the longitudinal chromatic aberration effected for an eye may be equal to, or more negative than, about -0.25 D, -0.5 D, -0.75 D, -1 D, -1.5 D, -2 D or -2.5 D between a longer wavelength and a shorter wavelength.

[00144] For some embodiments, the longitudinal chromatic aberration effected for an eye may be equal to, or more negative than, about -0.25 D, -0.5 D, -0.75 D, -1 D, -1.5 D, -2 D or -2.5 D between a red wavelength and a blue wavelength.

[00145] For some embodiments, the longitudinal chromatic aberration effected for an eye may be equal to, or more negative than, -0.25 D, -0.5 D, -0.75 D, -1 D, -1.5 D, -2 D or -2.5 D between a longer wavelength of about 520 nm, 540 nm, 560 nm, 580 nm, 600 nm, 620 nm, 640 nm, 660 nm, 680 nm, 700 nm, 720 nm, 740 nm, 760 nm or 780 nm and a shorter wavelength of about 380 nm, 400 nm, 420 nm, 440 nm, 460 nm, 480 nm, 500 nm, 520 nm, 540 nm, 560 nm or 580 nm.

[00146] For some embodiments, the longitudinal chromatic aberration effected for an eye may be equal to, or more negative than, -0.25 D, -0.5 D, -0.75 D, -1 D, -1.5 D, -2 D or -2.5 D between a longer wavelength of about 546 nm, 588 nm, 589 nm, 644 nm, 656 nm, 707 nm or 768 nm and a shorter wavelength of about 405 nm, 436 nm, 480 nm, 486 nm, 546 nm, 588 nm or 589 nm.

[00147] For some embodiments, the longitudinal chromatic aberration effected for an eye may be equal to, or more negative than, -0.1 D, -0.2 D, -0.3 D, -0.4 D, -0.5 D, -0.6 D, -0.7 D, -0.8 D, -0.9 D or -1 D between a longer wavelength of between about 534 nm and 545 nm or between about 560 nm and 580 nm and a shorter wavelength of between about 420 nm to 440 nm or between about 534 nm and 545 nm. [00148] For some applications, the amount of reversal in longitudinal chromatic aberration may be established and verified away from or without an eye. In those embodiments, the longitudinal chromatic aberration of the ophthalmic lens system is selected to be of a certain amount.

[00149] The ophthalmic lens system according to some embodiments is a positive or piano (i.e., 0 D) power ophthalmic lens system that has a negative longitudinal chromatic aberration.

[00150] The ophthalmic lens system according to some embodiments is a positive or piano (i.e. 0 D) power ophthalmic lens system that has a negative longitudinal chromatic aberration whereby the power for a longer wavelength is more positive than the power for a shorter wavelength that is equal to or greater than about 0.5 D, 1 D, 1.5 D, 2 D, 2.5 D, 3 D, 3.5 D, 4 D or 4.5 D.

[00151] The ophthalmic lens system according to some embodiments is a positive or piano (i.e. D) power ophthalmic lens system that has a negative longitudinal chromatic aberration of -0.5 D, -1 D, -1.5 D, -2 D, -2.5 D, -3 D, -3.5 D, -4 D or -4.5 D between a red wavelength and a blue wavelength.

[00152] The ophthalmic lens system according to some embodiments is a positive or piano (i.e. 0 D) power ophthalmic lens system that has a negative longitudinal chromatic aberration of -0.5 D, -1 D, -1.5 S, -2 D, -2.5 D, -3 D, -3.5 D, -4 D or -4.5 D between a longer wavelength of about 520 nm, 540 nm, 560 nm, 580 nm, 600 nm, 620 nm, 640 nm, 660 nm, 680 nm, 700 nm, 720 nm, 740 nm, 760 nm or 780 nm and a shorter wavelength of about 380 nm, 400 nm, 420 nm, 440 nm, 460 nm, 480 nm, 500 nm, 520 nm, 540 nm, 560 nm or 580 nm.

[00153] The ophthalmic lens system according to some embodiments is a positive or piano (i.e. 0 D) power ophthalmic lens system that has a negative longitudinal chromatic aberration of -0.5 D, -1 D, -1.5 D, -2 D, -2.5 D, -3 D, -3.5 D, -4 D or -4.5 D between a longer wavelength of about 546 nm, 588 nm, 589 nm, 644 nm, 656 nm, 707 nm or 768 nm and a shorter wavelength of about 405 nm, 436 nm, 480 nm, 486 nm, 546 nm, 588 nm or 589 nm. [00154] The ophthalmic lens system according to some embodiments is a positive or piano (i.e. 0 D) power ophthalmic lens system that has a negative longitudinal chromatic aberration of -0.1 D, -0.2 D, -0.3 D, -0.4 D, -0.5 D, -0.6 D, -0.7 D, -0.8 D, -0.9 D or -1 D between a longer wavelength of between about 534 nm and 545 nm or between about 560 nm and 580 nm and a shorter wavelength of between about 420 nm to 440 nm or between about 534 nm and 545 nm.

[00155] The ophthalmic lens system according to some embodiments is a negative power ophthalmic lens system that has a negative longitudinal chromatic aberration of - 1 D, -1.5 D, -2 D, -2.5 D, -3 D, -3.5 D, -4 D or -4.5 D between a longer wavelength and a shorter wavelength.

[00156] The ophthalmic lens system according to some embodiments is a negative power ophthalmic lens system that has a negative longitudinal chromatic aberration of - 1 D, -1.5 D, -2 D, -2.5 D, -3 D, -3.5 D, -4 D or -4.5 D between a red wavelength and a blue wavelength.

[00157] The ophthalmic lens system according to some embodiments is a negative power ophthalmic lens system that has a negative longitudinal chromatic aberration of - 1 D, -1.5 D, -2 D, -2.5 D, -3 D, -3.5 D, -4 D or -4.5 D between a longer wavelength of about 520 nm, 540 nm, 560 nm, 580 nm, 600 nm, 620 nm, 640 nm, 660 nm, 680 nm, 700 nm, 720 nm, 740 nm, 760 nm or 780 nm and a shorter wavelength of about 380 nm, 400 nm, 420 nm, 440 nm, 460 nm, 480 nm, 500 nm, 520 nm, 540 nm, 560 nm or 580 nm.

[00158] The ophthalmic lens system according to some embodiments is a negative power ophthalmic lens system that has a negative longitudinal chromatic aberration of - 1 D, -1.5 D, -2 D, -2.5 D, -3 D, -3.5 D, -4 D or -4.5 D between a longer wavelength of about 546 nm, 588 nm, 589 nm, 644 nm, 656 nm, 707 nm or 768 nm and a shorter wavelength of about 405 nm, 436 nm, 480 nm, 486 nm, 546 nm, 588 nm or 589 nm.

[00159] The ophthalmic lens system according to some embodiments is a negative power ophthalmic lens system that has a negative longitudinal chromatic aberration of - 0.1 D, -0.2 D, -0.3 D, -0.4 D, -0.5 D, -0.6 D, -0.7 D, -0.8 D, -0.9 D or -1 D between a longer wavelength of between about 534 nm and about 545 nm or between about 560 nm and about 580 nm and a shorter wavelength of between about 420 nm to about 440 nm or between about 534 nm and about 545 nm.

[00160] Measurement of the reversal of longitudinal chromatic aberration of the exemplary ophthalmic lens system may also be demonstrated in vivo.

[00161] For rapidly screening evaluation to determine whether an ophthalmic lens system imparts negative longitudinal chromatic aberration to an eye when in use by the eye, it may not be necessary to measure the actual amount of resultant ocular longitudinal chromatic aberration (i.e. the longitudinal chromatic aberration of the eye wearing the ophthalmic lens system) as demonstrated above. A qualitative method may suffice to verify or demonstrate a negative longitudinal chromatic aberration. For this method, the eye is given the refractive correction that achieves best vision for a chosen primary wavelength (for example, a green wavelength). The fogging technique (introduce or add positive power to the corrective lenses) is then used to reposition the foci for the shorter and longer wavelengths to be in front of the retina. In this state, the eye is typically unable to obtain clear images of light of the different wavelengths, so short, medium and long wavelengths images will appear blurred appear blurred. The fogging lens power is then gradually reduced to progressively bring the foci of the various wavelengths back towards the retina. If vision is first clearest for longer wavelength, then the eye with the ophthalmic lens system possess a net positive longitudinal chromatic aberration. If the vision is first clearest for the shorter wavelength, then the eye with the ophthalmic lens system exhibits a net negative longitudinal chromatic aberration. The test of clear vision for the shorter and longer wavelengths may be accomplished simultaneously, for example, by using targets that includes vision testing targets (e.g. Snellen acuity letters, 'illiterate E', Landolt "C", etc.) that are illuminated with the two different wavelengths on different target objects. Such instruments are common to many eye care clinics and known to eye care practitioners. One such instrument is the duochrome target. The duochrome target may consist of two sets of circular targets to test a patient's clarity of vision. One set of targets may be illuminated by light (or through filters) of one color or wavelengths (e.g. a shorter wavelength bluish-green color) and the other set of targets a different color or wavelength (e.g. a longer wavelength red color). Such an instrument allows the observer or patient to discern which wavelength target is relatively clearer.

[00162] Further advantages of the claimed subject matter will become apparent from the following examples describing certain embodiments of the claimed subject matter.

Example Set A :

Al. A spectacle lens system that is capable of reducing the rate of myopia progression in a person, comprising a spectacle lens; and at least one diffractive optical element. A2. The spectacle lens system of example Al, wherein the at least one diffractive optical element is an overlay that is applied to an anterior surface of the spectacle lens, a posterior surface of the spectacle lens or both.

A3. The spectacle lens system of examples Al or A2, wherein the at least one diffractive optical element is integrally formed with the spectacle lens.

A4. The spectacle lens system of examples Al or A3, wherein the at least one diffractive optical element is substantially located on the anterior surface of the spectacle lens, the posterior surface of the spectacle lens or both.

A5. The spectacle lens system of one or more of examples Al to A4, wherein the at least one diffractive optical element is located substantially within the interior of the spectacle lens.

A6. The spectacle lens system of one or more of examples Al to A5, wherein the at least one diffractive optical element covers at least 5%, 8%, 10%, 12%, 15%, 18%, 20%, 25%, 30%, 40% or 50% of the surface area the anterior surface of the spectacle lens, the posterior surface of the spectacle lens or both.

A7. The spectacle lens system of one or more of examples Al to A6, wherein the at least one diffractive optical element encompasses at least 10%, 15%, 20%, 25%, 30%, 40% 50%, 60%, 70%, 80%, 90% or 95% of the surface area the anterior surface of the spectacle lens, the posterior surface of the spectacle lens or both.

A8. The spectacle lens system of one or more of examples Al to A7, wherein the at least one diffractive optical element is capable of altering the chromatic aberration of a wearer over 10%, 15%, 20%, 25%, 30%, 40% 50%, 60%, 70%, 80%, 90% or 95% of the viewing angles available to the wearer when the spectacle lens system is being worn by the wearer for viewing by the wearer through the spectacle lens system.

A9. The spectacle lens system of one or more of examples Al to A7, wherein the at least one diffractive optical element is capable of altering the chromatic aberration of a wearer's eye over at least 10%, 15%, 20%, 25%, 30%, 40% 50%, 60%, 70%, 80%, 90% or 95% of the viewing angles available to the wearer when the spectacle lens system is being worn by the wearer for viewing by the wearer through the spectacle lens system.

A10. The spectacle lens system of one or more of examples Al to A9, wherein the spectacle lens system is comprised of 1, 2, 3 or 4 layers.

All. The spectacle lens system of one or more of examples Al to A10, wherein the material used to form the at least one diffractive optical element has a first power refractive index and the materials used to form the spectacle lens has a second refractive index and the first refractive index is different from the second refractive index.

A12. The spectacle lens system of one or more of examples Al to All, wherein the refractive index of the material used to form the at least 50%, 60%, 70%, 80% or 90% of the at least one diffractive optical element is different from the refractive index of the material used to form the spectacle lens.

A13. The spectacle lens system of one or more of examples Al to A12, wherein the at least one diffractive optical element is a plurality of diffractive optical elements and the plurality diffractive of optical elements have 1, 2, 3, 4 or 5 different diameters.

A14. The spectacle lens system of one or more of examples Al to A13, wherein the plurality of diffractive optical elements have 1, 2, 3, 4 or 5 different longitudinal chromatic aberration profiles.

A15. The spectacle lens system of one or more of examples Al to A14, wherein the plurality of diffractive optical elements have 1, 2, 3, 4 or 5 different focal lengths. A16. The spectacle lens system of one or more of examples Al to A15, wherein the spectacle lens system is capable of modifying incoming light through spectacle lenses and utilizes chromatic cues to decelerate the rate of myopia progression.

A17. The spectacle lens system of one or more of examples Al to A16, wherein the spectacle lens system is capable of providing a stop signal to a progressing eye for a substantial portion of the viewing angles of the spectacle lens system.

A18. The spectacle lens system of one or more of examples Al to A17, wherein the spectacle lens system is capable of providing the stop signal to the progressing eye for at least 95% of the total viewing angles of the spectacle lens system.

A19. The spectacle lens system of one or more of examples Al to A18, wherein the spectacle lens system is capable of providing the stop signal to the progressing eyes for the substantial portion of the viewing angles of a region of the spectacle lens system that contains the at least one diffractive optical element or the plurality of diffractive optical elements.

A20. The spectacle lens system of one or more of examples Al to A19, wherein the spectacle lens system is capable of providing the stop signal to the progressing eye for at least 95% of the total of the viewing angles of the region of the spectacle lens system that contains at least one diffractive optical element or the plurality of diffractive optical elements.

A21. The spectacle lens system of one or more of examples Al to A20, wherein the spectacle lens system is cosmetically substantially indistinguishable or indistinguishable from a commercial single vision spectacle lens.

A22. The spectacle lens system of one or more of examples Al to A21, wherein the spectacle lens system in normal use on a wearer's face and viewed by another person is cosmetically substantially indistinguishable or indistinguishable from the commercial single vision spectacle lens.

A23. The spectacle lens system of one or more of examples Al to A22, wherein the spectacle lens system is capable of providing the wearer with visual performance that is substantially indistinguishable or in or indistinguishable from a commercial single vision spectacle lens.

A24. The spectacle lens system of one or more of examples Al to A23, wherein the spectacle lens system in normal use on the wearer's face is capable of providing the wearer with visual performance that is substantially indistinguishable or indistinguishable from a commercial single vision spectacle lens.

A25. The spectacle lens system of one or more of examples Al to A24, wherein the system is capable of reversal of one or more longitudinal chromatic aberration of the wearer's eye for wavelengths in the region between approximately 450 nm and 660 nm.

A26. The spectacle lens system of one or more of examples Al to A25, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more red light wavelengths; and the one or more red light wavelengths are focused at positions in front of a retina of the wearer's eye.

A27. The spectacle lens system of one or more of examples Al to A26, wherein the one or more red light wavelengths is 656 nm or about 656 nm.

A28. The spectacle lens system of one or more of examples Al to A27, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more a green light wavelengths; and the one or more green light wavelengths are focused at positions located substantially on or close to the retina of the wearer's eye, but further from the ophthalmic lens system than positions the one or more red light wavelengths are focused.

A29. The spectacle lens system of one or more of examples Al to A28, wherein the one or more green light wavelength is 588 nm or about 588 nm.

A30. The spectacle lens system of one or more of examples Al to A29, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more blue light wavelengths; and the one or more blue light wavelengths are focused at positions in located substantially on or behind the retina.

Example Set B:

Bl. An ophthalmic lens configured for use on an eye comprising: a base lens with a focal power to correct, at least in part, the refractive error of the eye; and at least one diffractive optical element; wherein the at least one diffractive optical element reverses, or substantially reverses, at least in part a longitudinal chromatic aberration profile of the eye between the wavelengths 510 nm and 610 nm.

B2. An ophthalmic lens for an eye comprising: a base lens with a focal power to correct, at least in part, the refractive error of the eye; and at least one diffractive optical element; wherein the at least one diffractive optical element introduces at least 0.5D of reversal in the longitudinal chromatic aberrations of the eye that serves as a stop signal to retard the rate of progression of a myopic eye or an eye that may be progressing towards myopia.

B3. An ophthalmic lens that is capable of being used with an eye comprising: a base lens with a focal power to correct, at least in part, the refractive error of the eye; and at least one diffractive optical element; wherein the at least one diffractive optical element is capable of introducing at least 0.5D of reversal in the longitudinal chromatic aberrations of the eye between the wavelengths 510 nm and 610 nm.

B4. An ophthalmic lens of one or more examples Bl to B3, wherein the at least one diffractive optical element has an area at least 450,000 μιτι².

B5. An ophthalmic lens of one or more of examples Bl to B4, wherein the at least one diffractive optical element has a diameter of at least 750 μιτι.

B6. An ophthalmic lens of one or more of examples Bl to B5, wherein the at least one diffractive optical element covers at least 20%, 40%, 60% or 80% of a surface area of an anterior surface of the base lens, a posterior surface of the base lens or both. B7. An ophthalmic lens of one or more of examples Bl to B6, wherein the at least one diffractive optical element introduces a reversal in the one or more longitudinal chromatic aberrations of between 0.5D and 2.5D.

B8. An ophthalmic lens of one or more of examples Bl to B7, wherein the lens is a spectacle lens.

B9. An ophthalmic lens of one or more of examples Bl to B7, wherein the lens is a contact lens.

BIO. An ophthalmic lens of one or more of examples Bl to B8, wherein the at least one diffractive optical element is on the anterior surface of the spectacle lens.

Bll. An ophthalmic lens of one or more of examples Bl to B8, wherein the at least one diffractive optical element is on the anterior surface of the spectacle lens.

B12. An ophthalmic lens of one or more of examples Bl to B8, wherein the at least one diffractive optical element is on the posterior surface of the spectacle lens.

B13. An ophthalmic lens of one or more of examples Bl to B8, wherein the at least one diffractive optical element is at least in part embedded in the matrix of the base lens. B14. The ophthalmic lens of one or more of examples Bl to B13, wherein the ophthalmic lens is comprised of 1, 2, 3 or 4 layers.

B15. The ophthalmic lens of one or more of examples Bl to B14, wherein the base lens is comprised of 1, 2, 3 or 4 layers.

B16. The ophthalmic lens of one or more of examples Bl to B15, wherein the at least one diffractive optical element has one or more of the following shapes: circular, non- circular, oval, rectangular, hexagonal and square.

B17. The ophthalmic lens of one or more of examples Bl to B16, wherein the at least one diffractive optical element has an area of greater than 0.2, 0.3, 0.4, or 0.44 mm². B18. The ophthalmic lens of one or more of examples Bl to B17, wherein the at least one diffractive optical element has a diameter greater than 400, 500, 600, 700 or 750 μιτι. B19. The ophthalmic lens of one or more of examples Bl to B26, wherein the lens is configured to provide at least 0.5D reversal of the longitudinal chromatic aberrations of the eye in at least a portion of the peripheral region of the lens.

B20. A method for reducing the progression of myopia by using the ophthalmic lens of one or more of examples Bl to B19.

Example Set C:

CI. An ophthalmic lens system comprising: a lens having a first power and a first refractive index; and a diffractive optical element; wherein the lens and the diffractive optical element are selected such that when light passes through the system, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

C2. The ophthalmic lens system of example CI, wherein the lens and the diffractive optical element are adjoining, the lens and the diffractive optical element are spaced apart or the diffractive element is positioned within the lens or at least in part within the lens.

C3. The ophthalmic lens system of examples CI or C2, wherein longer wavelengths corresponding to red light are focused at positions located in front of the retina.

C4. The ophthalmic lens system of one or more of examples C1-C3, wherein shorter wavelengths corresponding to green light are focused at positions located substantially on the retina.

C5. The ophthalmic lens system of one or more of examples C1-C4, wherein short wavelengths corresponding to green light are focused at positions located in front of the retina, but further from the ophthalmic lens system than positions where longer wavelengths corresponding to red light are focused, during use to introduce myopic defocus.

C6. The ophthalmic lens system of one or more of examples C1-C5, wherein short wavelengths corresponding to blue light are focused at positions located substantially on or behind the retina during use.

C7. The ophthalmic lens system of one or more of examples C1-C6, wherein the ophthalmic lens system has a reversed longitudinal chromatic aberration that is substantially equal in magnitude but opposite in direction to a longitudinal chromatic aberration of a conventional plus lens and that has substantially greater reversal of longitudinal chromatic aberration of a conventional minus lens.

C8. The ophthalmic lens system of one or more of examples C1-C7, wherein the ophthalmic lens system is capable of being used to reduce the progression of myopia.

C9. The ophthalmic lens system of one or more of examples C1-C8, wherein the ophthalmic lens system is a single-vision ophthalmic lens.

CIO. The ophthalmic lens system of one or more of examples C1-C9, wherein the ophthalmic lens system is implemented within only a portion of visual fields of the ophthalmic lens system, such that when light passes through the portion of visual fields, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

Cll. The ophthalmic lens system of one or more of examples C1-C10, wherein the ophthalmic lens system is implemented within one or more regions such that when light passes through the one or more regions, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

C12. The ophthalmic lens system of one or more of examples Cl-Cll, wherein the diffractive optical element is incorporated into a plurality of lenslets that are distributed over at least a portion of the lens system.

C13. The ophthalmic lens system of one or more of examples C1-C12, wherein the ophthalmic lens system is one of a spectacle lens, a contact lens, a corneal onlay, a corneal inlay, or an intraocular lens.

C14. The ophthalmic lens system of one or more of examples C1-C13, wherein the lens with the first power and the first refractive index is a carrier lens.

C15. The ophthalmic lens system of one or more of examples C1-C14, wherein the lens has a negative power.

Example Set D:

Dl. An ophthalmic lens system for a human eye comprising: a base lens; at least one diffractive optical element; and the base lens and the at least one diffractive optical element are configured to include a reversal of the longitudinal chromatic aberration of a wearer's eye.

D2. The ophthalmic lens system of example Dl, wherein the reversal of the longitudinal chromatic aberration of the wearer's eye is defined for one or more wavelengths in the region between approximately 450 nm and 660 nm.

D3. The ophthalmic lens system of examples Dl or D2, wherein the reversal of the longitudinal chromatic aberration of the eye results in one or more wavelengths in the region of approximately 660 nm being positioned closer to the ophthalmic lens system and one or more wavelengths in the region of approximately 450 nm being positioned farther away from the ophthalmic lens system.

D4. The ophthalmic lens system of one or more of one or more of examples Dl to D3, wherein the one or more wavelengths in the region of approximately 660 nm correspond to red light and one or more wavelengths in the region of approximately 450 nm correspond to blue light.

D5. The ophthalmic lens system of any one of one or more of examples Dl to D4, wherein the reversal of the longitudinal chromatic aberration of the wearer's eye is about 0.5D to 2.5D.

D6. The ophthalmic lens system of one or more of examples Dl to D5, wherein the reversal of the longitudinal chromatic aberration of the wearer's eye is approximately 0.5D to 2D.

D7. The ophthalmic lens system of one or more of examples Dl to D6, wherein the reversal of the longitudinal chromatic aberration of the wearer's eye is approximately 0.5D to 1.5D.

D8. The ophthalmic lens systems of one or more of examples Dl to D7, wherein the reversal of the longitudinal chromatic aberration of the wearer's eye is approximately 0.5D to 1.5D and the red light is positioned closer to the ophthalmic lens system.

D9. The ophthalmic lens systems of one or more of examples Dl to D8, wherein the reversal of the longitudinal chromatic aberration of the wearer's eye is approximately 0.5D to 1.5D and the red light is positioned in front of a retina of the wearer's eye.

D10. The ophthalmic lens system of one or more of examples Dl to D9, wherein the diffractive optical element is configured with the base ophthalmic lens by one or more of the following: positioned adjacent to, closer to, attached, clipped, spaced-apart, coupled, applied as a film, etched or incorporated into the matrix of the base ophthalmic lens. Dll. The ophthalmic lens system of one or more of examples Dl to D10, wherein the diffractive optical element covers at least 20%, 30% 40%, 50%, 60%, 70%, 80% or 90% of a surface area of an anterior surface of the base lens, a posterior surface of the base lens or both.

Example Set E

El. An ophthalmic lens system comprising: a base lens; and at least one diffractive optical element; configured to result in a first power for longer wavelengths such as those corresponding to red light, a second power for shorter wavelengths such as blue light and a third power for medium wavelengths, such as those corresponding to green light, wherein the first power is substantially more positive (or less negative) than the third power and the second power is substantially more positive (or less negative) than the third power.

E2. The ophthalmic lens system of example El, wherein the at least one diffractive optical element is configured with the base lens by one or more of the following: positioned adjacent to, closer to, attached, clipped, spaced-apart, coupled, applied as a film, etched or incorporated into the matrix of the base lens.

E3. The ophthalmic lens system of examples El or E2, wherein the at least one diffractive optical element covers at least 20%, 30% 40%, 50%, 60%, 70%, 80% or 90% of a surface area of an anterior surface of the base lens, a posterior surface of the base lens or both.

E4. The ophthalmic lens system of one or more of examples El to E3, wherein the ophthalmic lens system is capable of being used to reduce the progression of myopia. E5. The ophthalmic lens system of one or more examples El to E4, wherein the at least one diffractive optical element has an area at least 450,000 μηη2. E6. The ophthalmic lens system of one or more of examples El to E5, wherein the at least one diffractive optical element has a diameter of at least 750 μιτι.

E7. The ophthalmic lens system of one or more of examples El to E6, wherein the at least one diffractive optical element is capable of altering the chromatic aberration of a wearer over 10%, 15%, 20%, 25%, 30%, 40% 50%, 60%, 70%, 80%, 90% or 95% of the viewing angles available to the wearer when the system is being worn by the wearer for viewing by the wearer through the spectacle lens system.

E8. The ophthalmic lens system of one or more of examples El to E7, wherein the at least one diffractive optical element is capable of altering the chromatic aberration of a wearer's eye over at least 10%, 15%, 20%, 25%, 30%, 40% 50%, 60%, 70%, 80%, 90% or 95% of the viewing angles available to the wearer when the ophthalmic lens system is being worn by the wearer for viewing by the wearer through the ophthalmic lens system. E9. The ophthalmic lens system of one or more of examples El to E8, wherein the at least one diffractive element is a plurality lenslets or a plurality of diffractive optical elements lenslets.

E10. The ophthalmic lens system of one or more of examples El to E8, wherein the ophthalmic lens system is comprised of 1, 2, 3 or 4 layers.

Ell. The ophthalmic lens system of one or more of examples El to E10, wherein the material used to form the at least one diffractive optical element has a first power refractive index and the materials used to form the ophthalmic lens has a second refractive index and the first refractive index is different from the second refractive index. E12. The ophthalmic lens system of one or more of examples El to Ell, wherein the refractive index of the material used to form the at least 50%, 60%, 70%, 80% or 90% of the at least one diffractive optical element is different from the refractive index of the material used to form the ophthalmic lens.

E13. The ophthalmic lens system of one or more of examples El to E12, wherein the at least one diffractive optical element the plurality of lenslets or plurality diffractive of optical elements have 1, 2, 3, 4 or 5 different diameters.

E14. The ophthalmic lens system of one or more of examples El to E13, wherein the plurality of diffractive optical elements have 1, 2, 3, 4 or 5 different longitudinal chromatic aberration profiles.

E15. The ophthalmic lens system of one or more of examples El to E14, wherein the plurality of lenslets or the plurality of diffractive optical elements have 1, 2, 3, 4 or 5 different focal lengths.

E16. The ophthalmic lens system of one or more of examples El to E15, wherein the ophthalmic lens system is capable of modifying incoming light through ophthalmic lenses and utilizes chromatic cues to decelerate the rate of myopia progression.

E17. The ophthalmic lens system of one or more of examples El to E16, wherein the ophthalmic lens system is capable of providing a stop signal to a progressing eye for a substantial portion of the viewing angles of the ophthalmic lens system.

E18. The ophthalmic lens system of one or more of examples El to E17, wherein the ophthalmic lens system is capable of providing the stop signal to the progressing eye for at least 95% of the total viewing angles of the ophthalmic lens system.

E19. The ophthalmic lens system of one or more of examples El to E18, wherein the ophthalmic lens system is capable of providing the stop signal to the progressing eyes for the substantial portion of the viewing angles of a region of the ophthalmic lens system that contains the at least one diffractive optical element or the plurality of diffractive optical elements.

E20. The ophthalmic lens system of one or more of examples El to E19, wherein the ophthalmic lens system is capable of providing the stop signal to the progressing eye for at least 95% of the total of the viewing angles of the region of the ophthalmic lens system that contains at least one diffractive optical element or the plurality of diffractive optical elements .

E21. The ophthalmic lens system of one or more of examples El to E20, wherein the ophthalmic lens system is cosmetically substantially indistinguishable or indistinguishable from a commercial single vision ophthalmic lens.

E22. The ophthalmic lens system of one or more of examples El to E21, wherein the ophthalmic lens system in normal use on a wearer's face and viewed by another person is cosmetically substantially indistinguishable or indistinguishable from the commercial single vision ophthalmic lens.

E23. The ophthalmic lens system of one or more of examples El to E22, wherein the ophthalmic lens system is capable of providing the wearer with visual performance that is substantially indistinguishable or in or indistinguishable from a commercial single vision ophthalmic lens.

E24. The ophthalmic lens system of one or more of examples El to E23, wherein the ophthalmic lens system in normal use on the wearer's face is capable of providing the wearer with visual performance that is substantially indistinguishable or indistinguishable from a commercial single vision ophthalmic lens.

E25. The ophthalmic lens system of one or more of examples El to E24, wherein the system is capable of reversal of one or more longitudinal chromatic aberration of the wearer's eye for wavelengths in the region between approximately 450 nm and 660 nm. E26. The ophthalmic lens system of one or more of examples El to E25, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more red light wavelengths; and the one or more red light wavelengths are focused at positions in front of a retina of the wearer's eye.

E27. The ophthalmic lens system of one or more of examples El to E26, wherein the one or more red light wavelengths is 656 nm or about 656 nm.

E28. The ophthalmic lens system of one or more of examples El to E27, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more a green light wavelengths; and the one or more green light wavelengths are focused at positions located substantially on or close to the retina of the wearer's eye, but further from the ophthalmic lens system than positions the one or more red light wavelengths are focused.

E29. The ophthalmic lens system of one or more of examples El to E28, wherein the one or more green light wavelength is 588 nm or about 588 nm. E30. The ophthalmic lens system of one or more of examples El to E29, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more blue light wavelengths; and the one or more blue light wavelengths are focused at positions in located substantially on or behind the retina. E31. An ophthalmic lens system comprising: a base lens; and a diffractive optical element; configured to result in a first power for a longer wavelength such as red light and a second power for a shorter wavelength such as blue light,

wherein the first power is more positive than the second power and the absolute difference between the first and second power is greater, or substantially greater, than the absolute value of the dioptric power equivalent to a longitudinal chromatic aberration of the eye and/or an eye corrected with a conventional lens system.

E32. An ophthalmic lens system of example E31, where in the longer wavelength is between 560 nm and 610 nm and the shorter wavelength is between 460 nm and 540 nm.

E33. The ophthalmic lens system of examples E31 or E32, wherein the absolute difference between the first and second power is at least 0.5 D.

E34. The ophthalmic lens system of one or more of examples E31 to E33, wherein the at least one diffractive optical element is configured with the base lens by one or more of the following: positioned adjacent to, closer to, attached, clipped, spaced-apart, coupled, applied as a film, etched or incorporated into the matrix of the base lens.

E35. The ophthalmic lens system of examples E31 or E34, wherein the at least one diffractive optical element covers at least 20%, 30% 40%, 50%, 60%, 70%, 80% or 90% of a surface area of an anterior surface of the base lens, a posterior surface of the base lens or both.

E36. The ophthalmic lens system of one or more of examples E31 to E35 wherein the ophthalmic lens system is capable of being used to reduce the progression of myopia.

E37. The ophthalmic lens system of one or more examples E31 to E36, wherein the at least one diffractive optical element has an area at least 450,000 μηη2. E38. The ophthalmic lens system of one or more of examples E31 to E37, wherein the at least one diffractive optical element has a diameter of at least 750 μιτι.

E39. The ophthalmic lens system of one or more of examples E31 to E38, wherein the at least one diffractive optical element is capable of altering the chromatic aberration of a wearer over 10%, 15%, 20%, 25%, 30%, 40% 50%, 60%, 70%, 80%, 90% or 95% of the viewing angles available to the wearer when the system is being worn by the wearer for viewing by the wearer through the spectacle lens system.

E40. The ophthalmic lens system of one or more of examples E31 to E39, wherein the at least one diffractive element is a plurality lenslets or a plurality of diffractive optical elements lenslets.

E41. The ophthalmic lens system of one or more of examples E31 to E40, wherein the ophthalmic lens system is comprised of 1, 2, 3 or 4 layers.

E42. The ophthalmic lens system of one or more of examples E31 to E41, wherein the material used to form the at least one diffractive optical element has a first power refractive index and the materials used to form the ophthalmic lens has a second refractive index and the first refractive index is different from the second refractive index.

E43. The ophthalmic lens system of one or more of examples E31 to E42, wherein the at least one diffractive optical element the plurality of lenslets or plurality diffractive of optical elements have 1, 2, 3, 4 or 5 different diameters.

E44. The ophthalmic lens system of one or more of examples E31 to E43, wherein the plurality of diffractive optical elements have 1, 2, 3, 4 or 5 different longitudinal chromatic aberration profiles.

E45. The ophthalmic lens system of one or more of examples E31 to E44, wherein the plurality of lenslets or the plurality of diffractive optical elements have 1, 2, 3, 4 or 5 different focal lengths.

E46. The ophthalmic lens system of one or more of examples E31 to E45, wherein the ophthalmic lens system is capable of modifying incoming light through ophthalmic lenses and utilizes chromatic cues to decelerate the rate of myopia progression. E47. The ophthalmic lens system of one or more of examples E31 to E46, wherein the ophthalmic lens system is capable of providing a stop signal to a progressing eye for a substantial portion of the viewing angles of the ophthalmic lens system.

E48. The ophthalmic lens system of one or more of examples E31 to E47, wherein the ophthalmic lens system is capable of providing the stop signal to the progressing eye for at least 95% of the total viewing angles of the ophthalmic lens system.

E49. The ophthalmic lens system of one or more of examples E31 to E48, wherein the ophthalmic lens system is cosmetically substantially indistinguishable or indistinguishable from a commercial single vision ophthalmic lens.

E50. The ophthalmic lens system of one or more of examples E31 to E49, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more red light wavelengths; and the one or more red light wavelengths are focused at positions in front of a retina of the wearer's eye.

E51. The ophthalmic lens system of one or more of examples E31 to E50, wherein the one or more red light wavelengths is 656 nm or about 656 nm.

E52. The ophthalmic lens system of one or more of examples E31 to E51, wherein the system is capable of: correcting vision of the wearer's eye; the reversal, or substantially reversal, of one or more longitudinal chromatic aberration for wavelengths corresponding to one or more blue light wavelengths; and the one or more blue light wavelengths are focused at positions in located substantially on or behind the retina.

E53. The ophthalmic lens system of one or more of examples El to E28, wherein the one or more blue light wavelength is 450 nm or about 450 nm.

Claims

1. An ophthalmic lens system comprising: a lens having a first power and a first refractive index; and a diffractive optical element; wherein the lens and the diffractive optical element are selected such that when light passes through the system, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

2. The ophthalmic lens system of claim 1, wherein the lens and the diffractive optical element are adjoining, the lens and the diffractive optical element are spaced apart or the diffractive element is positioned within the lens or at least in part within the lens.

3. The ophthalmic lens system of claims 1 or 2, wherein longer wavelengths corresponding to red light are focused at positions located in front of the retina.

4. The ophthalmic lens system of one or more of claims 1-3, wherein shorter wavelengths corresponding to green light are focused at positions located substantially on the retina.

5. The ophthalmic lens system of one or more of claims 1-4, wherein short wavelengths corresponding to green light are focused at positions located in front of the retina, but further from the ophthalmic lens system than positions where longer wavelengths corresponding to red light are focused, during use to introduce myopic defocus.

6. The ophthalmic lens system of one or more of claims 1-5, wherein short wavelengths corresponding to blue light are focused at positions located substantially on or behind the retina during use.

7. The ophthalmic lens system of one or more of claims 1-6, wherein the ophthalmic lens system has a reversed longitudinal chromatic aberration that is substantially equal in magnitude but opposite in direction to a longitudinal chromatic aberration of a conventional plus lens and that has substantially greater reversal of longitudinal chromatic aberration of a conventional minus lens.

8. The ophthalmic lens system of one or more of claims 1-7, wherein the ophthalmic lens system is capable of being used to reduce the progression of myopia.

9. The ophthalmic lens system of one or more of claims 1-8, wherein the ophthalmic lens system is a single-vision ophthalmic lens.

10. The ophthalmic lens system of one or more of claims 1-9, wherein the ophthalmic lens system is implemented within only a portion of visual fields of the ophthalmic lens system, such that when light passes through the portion of visual fields, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

11. The ophthalmic lens system of one or more of claims 1-10, wherein the ophthalmic lens system is implemented within one or more regions such that when light passes through the one or more regions, longer wavelengths are focused at positions closer to the lens system than shorter wavelengths.

12. The ophthalmic lens system of one or more of claims 1-11, wherein the diffractive optical element is incorporated into a plurality of lenslets that are distributed over at least a portion of the lens system.

13. The ophthalmic lens system of one or more of claims 1-12, wherein the ophthalmic lens system is one of a spectacle lens, a contact lens, a corneal onlay, a corneal inlay, or an intraocular lens.

14. The ophthalmic lens system of one or more of claims 1-13, wherein the lens with the first power and the first refractive index is a carrier lens.

15. The ophthalmic lens system of one or more of claims 1-14, wherein the lens has a negative power.