GB2555428A

GB2555428A - Transferable pupil position coordinate measurement system

Info

Publication number: GB2555428A
Application number: GB1618152.1A
Authority: GB
Inventors: Batham Philip
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-10-27
Filing date: 2016-10-27
Publication date: 2018-05-02
Also published as: GB201618152D0

Abstract

A device for holding the frame of spectacles or glasses in place for fitting of lenses, having a bridge rest post 2, two side rest posts 4, and a frame level slider bar 3. The sliding bar ensures the frame is horizontally level. A grid 1 gives a reference point for the lens measurements. The right and left side posts can be moved up and down independently to alter the tilt of the held frame. The lenses are pre-marked with the correct pupillary distance and optical height. The positions marked on the lenses are used to accurately site the lenses into the chosen glasses frames, with reference to the marked grid of the device. The pupillary distance and optical height are noted for future use. This method allows optical lenses to be fitted to a frame remotely from the customer or patient, without their presence being required. The noted measurements may subsequently be used as plotting points to find the correct optical centre for any other spectacle frame for the same customer, to glaze new lenses into the new frames. All measurements are taken separately for the left and right eyes to allow for facial asymmetry.

Description

(54) Title of the Invention: Transferable pupil position coordinate measurement system

Abstract Title: Device for positioning lenses in spectacles using pupillary distance measurement (57) A device for holding the frame of spectacles or glasses in place for fitting of lenses, having a bridge rest post 2, two side rest posts 4, and a frame level slider bar 3. The sliding bar ensures the frame is horizontally level. A grid 1 gives a reference point for the lens measurements. The right and left side posts can be moved up and down independently to alter the tilt of the held frame. The lenses are pre-marked with the correct pupillary distance and optical height. The positions marked on the lenses are used to accurately site the lenses into the chosen glasses frames, with reference to the marked grid of the device. The pupillary distance and optical height are noted for future use. This method allows optical lenses to be fitted to a frame remotely from the customer or patient, without their presence being required. The noted measurements may subsequently be used as plotting points to find the correct optical centre for any other spectacle frame for the same customer, to glaze new lenses into the new frames. All measurements are taken separately for the left and right eyes to allow for facial asymmetry.

Figi

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Figi

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Fig 2

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Background.

When spectacle frames have optical prescription lenses put in to them, the lenses are cut to the correct shape, orientation and are then inserted into the frame. Prescription lenses have an optical centre (OC), this is the point where the light passes through the lens and is focussed with the least amount of distortion. The optical centre of the lens is placed in line with the wearer’s pupil so that when they look straight ahead they look through the best point of the lens. This is important for all wearers so as to reduce induced prism which give rise to headaches, eyestrain, double vision and general optical discomfort.

Induced prism is where the eye is forced to look through a part of the lens other than the OC, this will move the position of the image away from the most sensitive part of the retina in the eye.

The horizontal measurement (X coordinate) component is termed as the pupillary distance (PD) (Diag) This is the distance between the centre of each pupil, this is often measured when looking in the distance, intermediate and near, or any other specific working distance. As the eyes come together (converge) when looking at nearer objects these figure are different. This PD is independent of the frame and can be measured once and used with any frame supplied by the customer.

The vertical measurement (Y coordinate) component is termed as the optical height (OH) (diag). This measurement has always been dependant on the frame. The OH is measured using the spectacle frame as the reference so will change depending on the shape and size of the frame. The OH measurement is not given to the wearer as it is specific to the frame they are using and can only be applied when making exactly the same frame shape and size.

The combination of these measurements when used together for each specific spectacle frame allow the manufacturer to place the optical centre perfectly in front of the pupil. This is very important when supplying higher powered prescription, bifocals, varifocals and other complicated lens forms.

The OH is measured when the glasses are dispensed which works well when the customer is present. For spectacle manufacturing companies that work without the customer present, making glasses where both the PD and OH is needed is not possible.

Statement of Invention.

To overcome the problem of spectacle manufacture where the PD and OH is required without the customer present. The invention proposes a method measuring the independent (independent of the frame) optical height (IOH). This can be re-plotted for any subsequent frame irrespective of frame shape size or type. This will allow the manufacturer of the spectacles to use both the PD and OH for any frame putting the optical centre of the lens directly in front of the wearer’s pupil.

If both the PD and IOH were measured when tested or dispensed then these could be used by any other manufacturer to make glasses very accurately. The invention allows the measurement of the IOH (that may be taken from an existing frame or a scaled image of the wearer with the frame) to be replicated to any other frame supplied.

Description.

If a frame is supplied with spectacle lenses in place the optical centre can be found using various standardised techniques. Once the optical centre is found the position can be plotted using X (PD) (Fig 3 No 1) & Y (OH) (Fig 3 No 2) coordinates. This can be replicated simply if supplying lenses for the same frame. If a different shaped frame is to be glazed with new lenses the PD can be used but not the OH with the current system.

The invention will be described by example and with reference to the drawings included.

Figure 1 shows the invention in front elevation, with the spectacle frame in place, resting on the fixed bridge post the base of the frame resting on the adjustable frame level slider bar.

Figure 2 shows the invention by side elevation with the sides of the frame resting on the adjustable side rest posts, frame is No 5.

Figure 3 shows the reference frame in front on the measuring grid with points plotted.

Figure 4 shows a different frame in front of the measuring grid with the new point plotted according to the measurements.

When the frame supplied, has the OC marked, it is placed on the device. The bridge of the frame is placed on the fixed bridge rest post (Fig 1&2 No 2), the sides of the frames are placed and the side rest posts (Fig 1&2 No 4) and the frame level slider bar (Figi&2 No 3) is lifted up so that it is touching the bottom most point of the frame. This ensures the frame is perfectly horizontally level. The right and left side rest posts can be moved up and down independently to allow for pantoscopic tilt of the frame. The millimetre (mm) (Fig 1 No 1) marked grid on the device can now be seen through the lens of the frame. The position marked on the lens can now be plotted using the mm scale on the device (Fig 3 No 3), now both a PD (x scale) and an IOH (y scale) can now be measured and noted (Fig 3 No 4).

When another frame is now placed on the device (Fig 4 No1), making sure it is fitted on the bridge rest post, side rest posts and the frame level slider bar is the same way. The same plotting points can now be plotted onto the new lens in the new frame (Fig 4 No2). This will give the new OC for the frame. This can then be used to glaze lenses into the frame. The OC for the new frame will now be in exactly the same position, in relation to the eyes, as it was for the first frame. The process can be repeated with any frame size or style.

All measurements are taken separately for left and right eyes as facial asymmetry is common.

Claims

Claims:

1. The device will allow the measurement of optical heights to be standardised (now referred to as IOH) like they are for the PD.

2. The device will allow the glazing of spectacles where both the PD and OH are required without the wearer to be present for measurements.

3. The device will allow IOH to be transferred to any other frame to be glazed with lenses requiring both PD and OH.

4. The device will allow the confirmation that the correct positioning of OC was observed while during spectacle glazing.

Intellectual

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