Measurement method for the determination of a value of a visual correction need for near vision of an individual

Patent metadata

Field	Value
Publication number	US-11278200-B2
Application number	US-201716333424-A
Country	US
Kind code	B2
Filing date	Sep 14, 2017
Priority date	Sep 15, 2016
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

Disclosed is a measurement method for determining a value of a visual correction need for near vision of an individual in a natural posture for near vision. A recognizing limit distance is determined so that the individual is able to recognize at least one predetermined symbol farther than the limit distance relatively to the individual and unable to recognize the at least one predetermined symbol closer to the individual than the limit distance. A portable medium displaying the predetermined symbol is displaced in front of the face and eyes of the individual to change a frontal distance between his/her eyes and the portable medium and in which when a recognizing limit distance is detected by the individual, the limit distance is measured and the value of the visual correction need is determined from the measured limit distance, wherein the visual correction need includes an accommodation compensation need.

First claim

The invention claimed is:

1. A measurement method for determining a value of a visual correction need for near vision of an individual for near vision wherein a recognizing limit distance is determined so that the individual is able to recognize at least one predetermined symbol disposed farther than said recognizing limit distance relatively to the individual and unable to recognize said at least one predetermined symbol disposed closer to the individual than said recognizing limit distance, the method comprising steps of:
displaying a portable medium configured to display said at least one predetermined symbol in front of a face and eyes of the individual to change a frontal distance between his/her eyes and the portable medium,
when the recognizing limit distance is detected by the individual, measuring said detected recognizing limit distance and determining the value of the visual correction need from said measured detected recognizing limit distance,
wherein said visual correction need comprises an accommodation compensation need, and
wherein the portable medium is an electronic device comprising at least a display screen, an optical sensor and an input interface, designed to perform that:
the display screen displays the at least one predetermined symbol,
the optical sensor records images of the face of the individual, at least while a distance between his/her eyes and the electronic device changes,
a computed distance between the eyes of the individual and the electronic device is computed from the images, and
when the input interface receives from the individual an entry corresponding to the detection by the individual of the recognizing limit distance, a corresponding computed distance is kept as being the measured detected recognizing limit distance and used to compute the value of the visual correction need, and

wherein the value of the visual correction need for the near vision is expressed as an ADDITION in diopter that is computed with:
ADDITION=1/(NV)−1/( D )

where NV is a near vision distance in length unit chosen for the individual and D is the measured detected recognizing limit distance.

2. The measurement method according to claim 1 , wherein the electronic device further comprises computation circuits with a microprocessor executing a program, the portable medium being designed to measure that at least the value of the visual correction need is computed by the computation circuits within the portable medium.

3. The measurement method according to claim 1 , wherein the electronic device further comprises a data communication interface for exchanging data to and from an external computer, the portable medium and the external computer being designed to measure that at least the value of the visual correction need is computed by the external computer.

4. The measurement method according to claim 1 , wherein the individual has an impaired far vision and wherein the individual is wearing a pair of glasses correcting his/her impaired far vision.

5. The measurement method according to claim 1 , wherein the individual has a perfect far vision and wherein the individual is not wearing a pair of glasses.

6. The measurement method according to claim 1 , wherein, in an initial step of the method, before the electronic device is displaced to change the distance between the eyes and the electronic device, the electronic device is calibrated to determine a projection ratio F in degrees per pixel.

7. The measurement method according to claim 6 , wherein, in an initial step of the method, before the electronic device is displaced to change the distance between the eyes and the electronic device, the electronic device is calibrated to determine the projection ratio F in degrees per pixel using a reference object of known size that is arranged to be imaged in the recorded images.

8. The measurement method according to claim 1 , wherein the computed distance that is kept as being the measured detected recognizing limit distance is an average of two computed distances, an up computed distance and a down computed distance, the up computed distance corresponding to the recognizing limit distance detected by the individual while the distance between his/her eyes and the electronic device increases starting with the electronic device closest to his/her face, the down computed distance corresponding to the recognizing limit distance detected by the individual while the distance between his/her eyes and the electronic device decreases starting with the electronic device farthest to his/her face, the input interface receiving from the individual an entry corresponding to the detection by the individual of the related recognizing limit distance for each of the increase and decrease of the distance.

9. The measurement method according to claim 1 , wherein the at least one predetermined symbol is selected from: characters, numerals, numbers, sentences of text, duochrome tests and images and wherein the electronic device is a smartphone or a tablet or a portable computer.

10. The measurement method according to claim 1 , wherein the input interface is configured to receive from the individual as the entry corresponding to the detection by the individual of the recognizing limit distance, an entry selected from: a push of a button of the electronic device, a release of a button of the electronic device, a voice input, a change in the visual expression of the face in the images, a rotation of the electronic device.

11. The measurement method according to claim 10 , wherein the change in the visual expression of the face in the images is selected from a prolonged closing of at least one eye, an opening of the mouth, a closing of the mouth, and a rotation of the face.

12. Electronic device that is a portable medium for determining a value of a visual correction need for near vision of an individual for near vision, said electronic device comprising at least a display screen, a mapping sensor, an input interface, and computation circuits with a microprocessor executing a program according to the measurement method of claim 1 .

13. A non-transitory computer-readable medium on which is stored a microprocessor program adapted to perform the measurement method of claim 1 when installed and executed in an electronic device that is a portable medium for determining a value of a visual correction need for near vision of an individual for near vision, said electronic device comprising at least a display screen, a mapping sensor, an input interface, and computation circuits with a microprocessor.

14. The measurement method according to claim 1 , wherein, in an initial step of the method, before the electronic device is displaced to change the distance between the eyes and the electronic device, the electronic device is calibrated to determine a projection ratio F in degrees per pixel, and the electronic device further comprises an inertial motion unit for recording motions of the electronic device, the determination of the projection ratio F is done by oscillating with rotation the electronic device and computation of recorded motions with reference to recorded related images from the optical sensor of the electronic device to quantify the displacement P in pixels of an object in the recorded images and the corresponding angular rotation A of said object, F being computed with F=A/P.

Assignees

• Essilor Int

Inventors

• Hernandez-Castaneda Martha
• Baranton Konogan
• Carrier John

Classifications

• A61B3/111

  for measuring interpupillary distance · CPC title

• A61B3/028

  for testing visual acuity; for determination of refraction, e.g. phoropters · CPC title

• A61B3/09 Primary

  for testing accommodation · CPC title

• A61B3/0041

  characterised by display arrangements · CPC title

• A61B2560/0431

  Portable apparatus, e.g. comprising a handle or case · CPC title