WO2002078529A1 - Method and device for assessing visual acuity - Google Patents
Method and device for assessing visual acuity Download PDFInfo
- Publication number
- WO2002078529A1 WO2002078529A1 PCT/NL2002/000214 NL0200214W WO02078529A1 WO 2002078529 A1 WO2002078529 A1 WO 2002078529A1 NL 0200214 W NL0200214 W NL 0200214W WO 02078529 A1 WO02078529 A1 WO 02078529A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- shape
- pixel size
- visual acuity
- background
- correction device
- Prior art date
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/02—Subjective types, i.e. testing apparatus requiring the active assistance of the patient
- A61B3/028—Subjective types, i.e. testing apparatus requiring the active assistance of the patient for testing visual acuity; for determination of refraction, e.g. phoropters
- A61B3/032—Devices for presenting test symbols or characters, e.g. test chart projectors
Definitions
- the present invention relates to a method and device for assessing the visual acuity of a person.
- European Patent Application EP-A 0 925 012 discloses a method and device for testing the visual acuity of a person by displaying symbols on a screen. Symbols, such as letters, numerals and the like, are displayed on the screen, both the background and the symbols being displayed on a screen with a fixed resolution (pixel size). Assessment of the visual acuity (near and far) takes place by means of an adjustable optical correction, through which the symbols on the screen are viewed. The symbols can be displayed in various sizes.
- European Patent Application EP-A 1 042 984 discloses a device for the presentation of an optometric card.
- the device is provided with separate test windows for the left and the right eye.
- An optotype consisting of a rotary optometric disc, is positioned optically a certain distance away from the windows. The test is conducted automatically, supported by verbal messages.
- the known optometers make use of known presentations of test objects, frequently in the form of printed cards with symbols, such as the Monnoyer card (distance test) or Parinaud card (test at reading distance).
- the accuracy of the known tests is sometimes insufficient, for example if a person is frequently tested using the same card symbols and, as it were, instead of the visual acuity, the person's memory is tested.
- the aim of the present invention is to provide an improved method and device for the assessment of visual acuity, in particular for the prescription of spectacle lenses or contact lenses.
- the present invention therefore provides, in a first aspect, a method for the assessment of visual acuity of a person, comprising the steps of displaying, at a preset distance, at least one shape on a background, the background being displayed with a first pixel size and the at least one shape with a second pixel size, the second pixel size being greater than the first pixel size, adjustment of a correction device for optical correction of the visual acuity until the at least one shape is distinguishable from the background, and determining the correction for visual acuity on the basis of the setting of the correction device.
- the visual acuity of a person can also be assessed by making use of a symbol or shape on a background, where the background has a finer pixel size than the shape. Because of the small pixel size, the background creates the impression of an even surface, against which the shape with the larger pixels stands out. Using this method the visual acuity can be determined more rapidly and more accurately. Subjective factors of recognition and the like play a lesser role, as a result of which a more objective assessment of the visual acuity becomes possible.
- the at least one shape can be a numeral, letter or a specific shape.
- the relative pixel density of the background and the at least one shape is essentially the same.
- the pixel density is defined as the number of pixels per unit surface area multiplied by the surface area of one pixel.
- Someone who is a long distance away or has poorly corrected eyes will in this case see both the background and the at least one shape as an even, homogeneous surface.
- Someone with good or properly corrected visual acuity will, however, detect a grainy shape against an even background.
- the background and the at least one shape are displayed using a combination of at least two colours of pixels.
- Black and white pixels will, for example, yield a grey background, yellow and blue pixels a green background and blue and black pixels a dark blue background. If the visual acuity is properly corrected the at least one shape will stand out against the background, as a grainy grey shape against the grey background, yellow and blue dots against a green background and blue pixels against a dark blue background.
- the background is displayed in a first colour and the at least one shape in at least a second colour.
- the background can, for example, consist of white pixels and the shape of black pixels, or vice versa.
- a further colour green, blue, red, ...
- adjustment of the correction device is preferably carried out a number of times and the corrections for visual acuity determined from the average of the respective settings of the correction device.
- a more accurate and objective assessment of the visual acuity becomes possible by this means.
- the method is carried out in an alternating manner, the at least one shape being displayed in a region of visible light with a short wavelength and in a region of visible light with a long wavelength. The refraction of the eye is dependent on the wavelength.
- two measurements are carried out at the ends of the visible spectrum and, for example, the average is taken as the result.
- the at least one shape can be displayed in a number of variants.
- the at least one shape can be displayed alternately with the first and the second pixel size, for example with a frequency of less than 10 Hertz.
- the flashes of the shape with the second pixel size are discernible only to a person with good (corrected) visual acuity. It is also possible to make the at least one shape turn in the display or to make the at least one shape move (back and forth, up and down) in the display. All these variants increase the unpredictability of the measurement and thus give a more objective assessment of the visual acuity.
- the at least one shape comprises parallel lines that are displayed such that they can be turned between 0 and 180 degrees. The shape is then most clearly visible when the lines run parallel to the axis of the astigmatism of the eye.
- the person to be tested can change the orientation of the parallel lines in the shape him- or herself, for example with the aid of a joystick.
- the second pixel size is variable.
- the present invention relates to a device for the assessment of visual acuity of a person, comprising a correction device with an adjustable optical correction for visual acuity, a display screen that is placed a predetermined distance away from the correction device, and control means that are connected to the display screen and the correction device, the control means being equipped to control the display screen and to control the correction device according to the present method.
- a correction device with an adjustable optical correction for visual acuity
- a display screen that is placed a predetermined distance away from the correction device
- control means that are connected to the display screen and the correction device, the control means being equipped to control the display screen and to control the correction device according to the present method.
- the device further comprises an optical system that is equipped for projection of the display screen at reading distance from the correction device.
- the present invention relates to an optometric card comprising a background with a first pixel size and at least one shape with a second pixel size, the second pixel size being larger than the first pixel size.
- This card can be used in existing devices for the assessment of visual acuity, as a replacement for the existing optometric cards.
- FIG. 1 shows a simplified representation of a set-up of the device according to the present invention.
- a simple representation of a possible set-up of a device 10 according to the present invention is shown in Fig. 1.
- a display screen 12 is arranged a predetermined distance 1, for example four metres, away from a correction device 13.
- a user of the device is able to look through an opening 14 in the correction device 13 towards the display screen 12.
- Optical correction lenses the strength of which is adjustable (by, for example, adding lenses) can be placed in the opening 14.
- the opening 14 is made for two eyes, the two halves of the opening 14 being adjustable independently of one another.
- the display screen 12 and the correction device 13 are connected to a control device 11.
- the control device 11 controls the setting of the correction device 13 as a function of input signals which, for example, are received via an adjuster element 17, such as a joystick, that is connected to the control device 11.
- the control device 11 also controls the display screen 12.
- the control device 11 can be provided with memory means in some form or other (such as RAM memory, a DVD, video tape, etc.). These can be used, on the one hand, for recording results obtained and, on the other hand, for driving the control device 11 on the basis of a stored program.
- the device 10 is preferably set up in a somewhat darkened room.
- the control device 11 controls the display screen 12 in such a way that a shape 16 (or multiple shapes) is displayed on a background 15.
- the background 15 is displayed with a specific pixel size, as a result of which, some distance away, this gives the impression of an even surface.
- the shape 16 is displayed with (a smaller number of) larger pixels. The pixel size of the shape 16 is thus larger than the pixel size of the background 15.
- the relative pixel densities of the background and of the at least one shape are essentially the same.
- the pixel density is defined as the number of pixels per unit surface area multiplied by the surface area of one pixel.
- the shape 16 can be a numeral or letter, or the outlines of an everyday article.
- the shape 16 is of a size such that a large part of the background 15 is covered.
- the control device 11 controls the display screen 12 in such a way that the shape 16 is preferably varied so that this is unpredictable for the person.
- the shape 16 is visible only if the visual acuity of the person is good or has been well corrected, so that the resolving power of the eyes is able to differentiate the coarser pixels of the shape 16.
- the person is able to vary the strength of the correction lenses in the correction device 13 with the aid of the adjuster element 17 and is also able to indicate when the shape 16 is most clearly visible to him or her.
- the person can indicate outer limits, that is to say when the shape 16 becomes visible and when it disappears.
- the control device 11 can then, for example, calculate a mid position which indicates the proper correction for the person.
- the shape 16 is preferably displayed in a different colour from the background 15 (for example white shape 16 on black background 15, or vice versa).
- the shape 16 can also be displayed in more than one colour, as a result of which it stands out better against the background 15.
- two measurements are carried out by the device 10 in question.
- the shape 16 is displayed in a colour of visible light with a short wavelength, for example violet-blue.
- the shape 16 is displayed in a colour at the other end of the visible spectrum, for example in red.
- the refraction of the lens of the eye differs for different wavelengths and by means of the two measurements in violet-blue and in red the ideal correction value can be calculated (for example as an average).
- the shape 16 can be displayed alternately with the fine pixels and with the coarse pixels, with a frequency of, for example, less than 10 times per second.
- the shape 16 displayed as flashes is visible only if the visual acuity has been well corrected.
- the control device 11 can also be equipped to make the shape turn in the display, the shape 16 being, for example, a rotating cross, a rotating wheel with spokes, or rotating windmill sails. It is also possible to display the shape 16 as a moving shape 16. This ensures that the display of shape 16 is even more unpredictable, as a result of which the measurement with the device 10 in question can be carried out more objectively. In a special embodiment of the present invention the degree of astigmatism can also be determined. In this case the shape 16 is displayed on the display screen 12 as a shape with thin parallel lines. The angle of the parallel lines can be adjusted, for example by means of the abovementioned adjuster element 17.
- the parallel lines of the shape 16 are clearest to the person when these run parallel to the axis of the astigmatism. With the aid of the adjuster element 17 the person is able to indicate when the shape 16 is clearest, after which the control means 11 determine the best correction.
- the visual acuity of a person can be measured quantitatively by varying the pixel size of the shape 16.
- the visual acuity is determined by determining the smallest pixel size at which the person still sees a distinction between the shape 16 and the background 15.
- the present invention can also be used to determine the visual acuity of a person for prescribing reading glasses.
- the display screen 12 is projected, for example by means of an optical system (with the use of lenses and/or mirrors, not shown) onto a matt glass screen that is located at reading distance from the opening 14 in the correction device 13.
- the image is reduced to such an extent that the angle of vision for the person remains the same.
- spoken instructions can be made audible.
- the instructions contain indications of what the user must look out for and how the device 10 must be operated. It is also possible to ask which numeral, letter or shape is detected. The user can input this into the device 10 with the aid of a speech recognition module or another input device. The input can then be recorded.
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- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Medical Informatics (AREA)
- Biophysics (AREA)
- Ophthalmology & Optometry (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
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Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP02718705A EP1372462B1 (en) | 2001-03-30 | 2002-04-02 | Method and device for assessing visual acuity |
DE60205730T DE60205730T2 (en) | 2001-03-30 | 2002-04-02 | METHOD AND DEVICE FOR DETECTING THE SEA SHARPNESS |
AT02718705T ATE302563T1 (en) | 2001-03-30 | 2002-04-02 | METHOD AND DEVICE FOR DETECTING VISUAL ACUITY |
HK04104673A HK1061636A1 (en) | 2001-03-30 | 2004-06-30 | Method and device for assessing visual acuity. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL1017741 | 2001-03-30 | ||
NL1017741A NL1017741C2 (en) | 2001-03-30 | 2001-03-30 | Method and device for assessing visual acuity. |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2002078529A1 true WO2002078529A1 (en) | 2002-10-10 |
Family
ID=19773161
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/NL2002/000214 WO2002078529A1 (en) | 2001-03-30 | 2002-04-02 | Method and device for assessing visual acuity |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP1372462B1 (en) |
AT (1) | ATE302563T1 (en) |
DE (1) | DE60205730T2 (en) |
HK (1) | HK1061636A1 (en) |
NL (1) | NL1017741C2 (en) |
WO (1) | WO2002078529A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007009736A1 (en) * | 2005-07-19 | 2007-01-25 | Carl Zeiss Vision Gmbh | Method and device for testing scotopic vision |
CN109645952A (en) * | 2017-10-12 | 2019-04-19 | 李长良 | Green background eyesight detects lamp box |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107837068B (en) * | 2017-11-27 | 2019-08-09 | 绍兴市寅川软件开发有限公司 | A kind of eyesight detection lamp box |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0261963A2 (en) * | 1986-09-26 | 1988-03-30 | Stereo Optical Company, Inc. | Visual acuity test device and method of preparing same |
US5515118A (en) * | 1988-12-12 | 1996-05-07 | Prio Corporation | Reflective stimulus for computer screen simulation for eye examinations |
US5530492A (en) * | 1993-03-22 | 1996-06-25 | Medoptics Limited | Ophthalmological instrument for producing dichoptic stimuli on a visual display terminal |
WO1998018381A1 (en) * | 1996-10-30 | 1998-05-07 | Mentor Corporation | Visual acuity tester |
EP0911792A2 (en) * | 1997-10-22 | 1999-04-28 | Carl Zeiss | Method of forming an image on a colour screen and appropriate colour screen |
EP0925012A1 (en) * | 1997-05-02 | 1999-06-30 | Mutualite de l'Anjou | Method for testing a person's sight, and corresponding calibrating standard |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1042984B1 (en) | 1999-04-06 | 2005-06-08 | Nidek Co., Ltd. | Optometric chart presenting apparatus |
-
2001
- 2001-03-30 NL NL1017741A patent/NL1017741C2/en not_active IP Right Cessation
-
2002
- 2002-04-02 DE DE60205730T patent/DE60205730T2/en not_active Expired - Lifetime
- 2002-04-02 WO PCT/NL2002/000214 patent/WO2002078529A1/en not_active Application Discontinuation
- 2002-04-02 EP EP02718705A patent/EP1372462B1/en not_active Expired - Lifetime
- 2002-04-02 AT AT02718705T patent/ATE302563T1/en not_active IP Right Cessation
-
2004
- 2004-06-30 HK HK04104673A patent/HK1061636A1/en not_active IP Right Cessation
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0261963A2 (en) * | 1986-09-26 | 1988-03-30 | Stereo Optical Company, Inc. | Visual acuity test device and method of preparing same |
US5515118A (en) * | 1988-12-12 | 1996-05-07 | Prio Corporation | Reflective stimulus for computer screen simulation for eye examinations |
US5530492A (en) * | 1993-03-22 | 1996-06-25 | Medoptics Limited | Ophthalmological instrument for producing dichoptic stimuli on a visual display terminal |
WO1998018381A1 (en) * | 1996-10-30 | 1998-05-07 | Mentor Corporation | Visual acuity tester |
EP0925012A1 (en) * | 1997-05-02 | 1999-06-30 | Mutualite de l'Anjou | Method for testing a person's sight, and corresponding calibrating standard |
EP0911792A2 (en) * | 1997-10-22 | 1999-04-28 | Carl Zeiss | Method of forming an image on a colour screen and appropriate colour screen |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007009736A1 (en) * | 2005-07-19 | 2007-01-25 | Carl Zeiss Vision Gmbh | Method and device for testing scotopic vision |
US9259145B2 (en) | 2005-07-19 | 2016-02-16 | Carl Zeiss Vision Gmbh | Apparatus and method for testing night vision |
US9717407B2 (en) | 2005-07-19 | 2017-08-01 | Carl Zeiss Vision Gmbh | Apparatus and method for testing night vision |
CN109645952A (en) * | 2017-10-12 | 2019-04-19 | 李长良 | Green background eyesight detects lamp box |
Also Published As
Publication number | Publication date |
---|---|
ATE302563T1 (en) | 2005-09-15 |
EP1372462A1 (en) | 2004-01-02 |
DE60205730D1 (en) | 2005-09-29 |
NL1017741C2 (en) | 2002-10-01 |
HK1061636A1 (en) | 2004-09-30 |
DE60205730T2 (en) | 2006-05-18 |
EP1372462B1 (en) | 2005-08-24 |
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