ES2947436A1 - COMPUTER IMPLEMENTED METHOD FOR INTERACTIVELY MEASURING ONE OR BOTH EDGES OF THE INTERVAL OF SHARP VISION OF THE USER'S EYE BY MEANS OF AN ELECTRONIC DEVICE, SYSTEM, AND COMPRISING ELECTRONIC DEVICE (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

A computer-implemented method of interactively measuring one or both edges of the sharp vision interval of a user's eye by an electronic device, system, and electronic device. It is measured without the need for an optical component that changes the vergence of the rays that originate from a stimulus. A system using such a method and the age of the wearer can estimate the sphero-cylindrical refraction, the sum and the power of the wearer's reading glasses. Different sizes, directions and colors of stimuli can be used which can change with distance or user interaction. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

COMPUTER IMPLEMENTED METHOD FOR INTERACTIVELY MEASURING ONE OR BOTH EDGES OF THE INTERVAL OF CLEAR VISION OF A USER'S EYE USING

AN ELECTRONIC DEVICE, SYSTEM AND ELECTRONIC DEVICE THAT

UNDERSTANDS

FIELD OF THE INVENTION

The invention is related to the fields of optometry, visual optics, physiological optics, electronics and computing. In particular, it is related to the systems and methods of measuring the near and far point of a human eye and its focusing errors, which can cause myopia, hyperopia, astigmatism and presbyopia.

BACKGROUND OF THE INVENTION

A perfect eye forms images of infinitely distant objects accurately on the retina. Therefore, the remote point (FP) of a perfect eye is located at infinity. As the distance between the eye and an object decreases, the eye keeps the object in focus through accommodation, which is a process that primarily changes the curvature of a lens within the eye. Once a minimum accommodating distance is reached and the lens can no longer curve, an object is located at the eye's proximal point (NP). In optometry, distances are often expressed in units of diopters (D), which are the inverse of meters (m). The dioptric distance between FP and NP of an eye is called the accommodation amplitude (AA). Since the FP of a perfect eye is located at infinity, this corresponds to 0 D. An NP of a perfect eye can, for example, be located at a distance of 0.1 m, which corresponds to 10 D. In this case AA = NP -FP = 10 D.

Eyes age and people who are approximately 45 years old or older suffer from presbyopia - a condition in which the lens of the eye loses the ability to change shape. The amplitude of accommodation of the eyes decreases with age from approximately 20 D in childhood to 0 D in late adulthood, when the eye loses the ability to form sharp images of nearby objects on the retina. There are many reports documenting the relationship between age and the maximum change in accommodation in human eyes [1] [2].

In addition, the eyes suffer from focusing errors caused by optical imperfections in their refractive surfaces (cornea and lens) and/or by a mismatch between the refractive power and the axial length of the eye, which are called refractive errors. Such errors, which cause the far point to be located closer than infinity ( myopia) or farther than infinity ( hyperopia), prevent the eye from accurately forming images on the retina and result in deterioration in quality. visual and require optical correction.

Refractive errors that can be corrected with glasses, contact lenses, intraocular lenses or refractive surgery can be divided into spherical errors (myopia or hyperopia), cylindrical errors ( astigmatism) and presbyopia. Astigmatism is a condition in which the optical power of the eye varies with the meridian (orientation), causing the remote point to divide into two ( meridians ); one corresponding to, for example, horizontal, and the other corresponding to vertical components of the image. This causes the visual quality of images of vertical objects (for example, a fence) to be different from the visual quality of images of horizontal objects (for example, a striped dress) and can lead to nausea, double viewing and a general loss of visual quality. Many authors have shown that the magnitude and axis of astigmatism do not change much during accommodation [3] [4].

The fact that astigmatism can be present in both relaxed and accommodating eyes means that both the FP and NP can split. Each one can correspond to two distances depending on the orientation of the object; distal remote point (dFP) and proximal remote point (pFP), and distal proximal point (dNP) and proximal proximal point (pNP). These four distances correspond to the extremes of the interval of clear vision (BICV). The first two are on the far side and the last two on the near side of the interval of clear vision (SICV).

Due to the chromatic dispersion of light from ocular media, which is a function of wavelength, the positions of the FP and NP depend on the spectral composition (color) of the object [5] captured by the optics of the eye on the retina. For example, in the case of a 2D myope looking at an object on a black background, an FP can be located at a distance of 0.5 m, 0.4 m, and 0.53 m for white, blue, and red objects, respectively. Ocular chromatic dispersion is known and similar between subjects, so FP and NP can be calculated for any given wavelength (color) [6].

Prior to its correction, the type and amount of refractive error must be determined through a procedure known as refraction, which consists of finding the combination of spherical and cylindrical lenses that corrects the eye's focusing errors described above. Refraction is performed using specific optical instruments, which can measure the light leaving the eye ( objective refraction), or by trained specialists using an optotype and a set of trial lenses ( subjective refraction ).

The human eye never achieves perfect focus, even after sphero-cylindrical correction, due to the presence of higher-order monochromatic aberrations [7] and errors in both objective and clinically determined subjective refractions that have been documented [8, 9]. Furthermore, optimal refractions may also vary with the task and object being viewed [10]. For example, if the objective of refraction is to read optotypes or letters, it will depend on the size of the letter. Low myopes can read large print without correction, but need correction for small print. Similarly, low presbyopes can read medium-sized letters or big, but not small. Therefore, the position of FP and NP depends on both the size of the object [11] and the refraction of the subject.

BIBLIOGRAPHIC REFERENCES

1. Duane A. Studies in Monocular and Binocular Accommodation, with Their Clinical Application.

Transactions of the American Ophthalmological Society. 1922; 20:132-57.

2. Jackson E. Amplitude of Accommodation at Different Periods of Life. California state journal of medicine. 1907; 5(7):163-6.

3. Borish IM. Clinical refraction, 3rd ed. Chicago: Professional Press, 1970.

4. Bannon RE. A study of astigmatism at the near point with special reference to astigmatic accommodation. Am J Optom Arch Am Acad Optom. 1946; 23:53-75.

5. Sivak JG, Mandelman T. Chromatic dispersion of the ocular media. Vision Res 1982; 22:997-1003.

6. Thibos LN, Ye M, Zhang X, Bradley A. The chromatic eye: a new reduced-eye model of ocular chromatic aberration in humans. Appl Opt 1992; 31:3594-3600.

7. Charman WN. Wavefront aberration of the eye: a review. Optom Vis Sci 1991; 68:574-583. 8. Bullimore, M.A., Boyd, T., Mather, H.E., & Gilmartin, B. (1988). Near retinoscopy and refractive error. Clinical and Experimental Optometry, 71(4), 114-118.

9. Bullimore, MA, Fusaro, RE, & Adams, CW (1998). The repeatability of automated and clinical refraction. Optometry and vision science: official publication of the American Academy of Optometry, 75(8), 617-622.

10. López-Gil, N., Peixoto-de-Matos, S. C., Thibos, L. N., & González-Méijome, J. M. (2012).

Shedding light on night myopia. Journal of Vision, 12 (5):4, 1-9.

11. Heath G.G. (1956). The influence of visual acuity on accommodation responses of the eye. A.M.

J. Opt&t. & drchs Am. Acad. Oprom. 33. 513-524.

OBJECT OF THE INVENTION

The present invention relates to computer-implemented methods and systems for interactively measuring one or both edges of the eye's clear vision range. The methods are based on measurements of the distance between a subject's head and an electronic device corresponding to one or both SICVs, which represent measurements of ray vergence.

The system proposed in this document may include the following components of an electronic device:

to. Distance measurement circuits, which may include passive components such as one or more cameras, or active components such as emitters, detectors or others, or any combination thereof.

b. User interface, which may include an electronic display with a touch surface or a keyboard or a microphone, or others, or any combination thereof.

c. Control circuits and processing circuits, which may include processors, memory modules, wired or wireless connections between modules and system components and remote networks, or others, or any combination thereof.

The method proposed in this document may comprise the steps of:

to. Acquire information about a user, such as age (AGE), gender, geographic location, eye to be examined or others, or any combination thereof.

Yo. According to some embodiments of the present invention, acquiring information about a user comprises configuring a user interface module to request the user to enter said information into a user interface.

ii. According to some embodiments of the present invention, acquiring information about a user comprises automatically detecting said information based on an image of a user's head from a camera included in an electronic device or other databases.

iii. According to some embodiments of the present invention, acquiring information about a user comprises configuring a connectivity and/or storage module to retrieve said information from a local or remote server or memory.

b. Display a stimulus on an electronic screen, such as one or more letters or optotypes, a geometric pattern or a still or moving image, or other, or any combination thereof.

Yo. According to some embodiments of the present invention, displaying a stimulus on an electronic display comprises changing the size, shape, rotation, color, background color, or other characteristics such as spatial frequency of one or more components of the stimulus. or background, or any combination of any of the above in accordance with a user interaction with an electronic device using a user interface.

ii. According to some embodiments of the present invention, displaying a stimulus on an electronic display comprises changing the size, shape, rotation, color, background color, or other characteristics such as spatial frequency of one or more components of the stimulus. or of the fund, or any combination of any of the above with a change in distance between a user's head and an electronic device.

c. Changing the distance between a user's head and an electronic device displaying a stimulus until a subjective criterion of visual quality is met or no longer met.

Yo. According to some embodiments of the present invention, changing the distance between a user's head and an electronic device comprises holding a device in a user's hand and moving it toward or away from the user's head.

ii. According to some embodiments of the present invention, changing the distance between a user's head and an electronic device comprises positioning one or more reflective surfaces, the electronic device, and changing a distance between the device and the surface or a distance between the head and the surface, or any combination thereof.

iii. According to some embodiments of the present invention, changing the distance between a user's head and an electronic device comprises changing the distance by a third party, such as another person, another device, or another device, or any combination of any of the above.

d. Measurement of the position of one or both SICVs when a certain criterion of visual quality with respect to the stimulus is met or no longer met.

Yo. According to some embodiments of the present invention, measuring the position of one or both SICVs may comprise displaying on an electronic display to a user a stimulus with spatial features oriented at a certain angle a and measuring a corresponding distance between the user and the stimulus.

ii. According to some embodiments of the present invention, measuring the position of one or both SICVs may further comprise displaying a stimulus with spatial detail to a user at a different angle p, which may be perpendicular to angle a (angle with the horizontal measured at counterclockwise), and measure a corresponding distance between the user and the stimulus.

iii. According to some embodiments of the present invention, measuring the position of one or both SICVs may comprise configuring a distance measurement circuit included in the electronic device to perform measurements.

iv. According to some embodiments of the present invention, measuring the position of one or both SICVs may comprise the use of an external apparatus for making measurements, such as a ruler, rangefinder or other, or any combination of any of the above.

v. According to some embodiments of the present invention, the visual quality criterion may comprise a visual acuity criterion (for example, resolution of lines, letters, etc.), a contrast sensitivity criterion (for example, distinguishing shades of gray), a color discrimination criterion (e.g., distinctive colors), subjective clarity, or others, or any combination of any of the above.

saw. According to some embodiments of the present invention, satisfying or failing to satisfy a certain visual quality criterion with the stimulus may comprise a continuous evaluation of the stimulus by the user when the distance between the user's head and the device is changed. For example, the user may stop seeing a fine spatial pattern in the stimulus at a certain distance as it moves away from the user's head and becomes blurred.

BRIEF DESCRIPTION OF THE FIGURES

The following figures accompanying the detailed description serve to further illustrate the nature of the present invention and its advantages:

FIG. 1 is a schematic of an illustrative system for interactively measuring one or both edges of the eye's range of clear vision with an embodiment of the invention.

FIG. 2 is a block diagram of an illustrative electronic device for interactively measuring one or both edges of the eye's clear vision range according to an embodiment of the invention where a camera is included in the distance measurement module and a display is included in the user interface.

FIG. 3 is an exemplary view of an illustrative display of an electronic device for interactively measuring one or both edges of the eye's clear vision range in accordance with one embodiment of the invention.

FIG. 4 is a flow chart of an illustrative subprocess for changing a stimulus with the distance between a head and an electronic device according to an embodiment of the invention.

FIG. 5 is a flow chart of an illustrative process for interactively measuring one or both edges of the eye's clear vision range in accordance with one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to computer-implemented systems and methods for interactively measuring one or both edges of the eye's clear vision range. The method is based on interactive measurements of the distance between a user's head and an electronic device, specifically corresponding to one or both SICVs. The present invention, in some embodiments thereof, may provide systems to allow users to accurately measure refractive errors or amplitude of accommodation with or without using optical correction, or addition, or the power of their reading glasses, in their own eyes in the other people's eyes.

FIG. 1 is a schematic of an illustrative computer-implemented system for interactively measuring one or both edges of the eye's clear vision range in accordance with an embodiment of the invention. The system 100 may include distance measurement circuits 110 , user interface 120 , control circuits 130 , processing circuits 140 , storage 150 , and communications circuits 160 . In some embodiments, one or more of the components of the device may be combined or omitted. In some embodiments, system 100 may include additional components not included in FIG. 1 , or a combination of any of the aforementioned components.

System 100 may include any suitable type of electronic device with distance measurement circuitry used to measure the distance between the user's head and the device. For example, system 100 may include any of the following devices equipped with a camera: a mobile phone, a tablet, a "smart" television, a personal digital assistant (PDA), a laptop or desktop computer, a camera or recorder video, and any other suitable device. The electronic device included in system 100 is preferably, but not limited to, a portable device.

The distance measurement circuitry 110 may include any circuitry, emitters and detectors for measuring the distance between the user's head or part thereof and the electronic device. In some embodiments, the distance measurement circuitry 110 may include a passive system comprising one or more cameras for capturing images of the user's head and circuitry for calculating the distance between the user's head or part thereof and the device from of said images. In some embodiments, the distance measurement circuitry 110 may include an active system comprising one or more emitters and detectors for measuring said distance.

User interface 120 may include any mechanism suitable for interaction with a user, such as one or more displays, speakers, touch surfaces, keyboards, microphones or others, or any combination thereof. For example, in some embodiments, user interface 120 may include an electronic touch screen for displaying stimuli and receiving user information.

Control circuitry 130 may include any type of circuitry, such as processors, microcontrollers, and connections to control the functions, operations, and performance of an electronic device included in system 100 . Additionally, the control circuitry 130 may be electronically coupled to other components of the system 100 , or any combination thereof. For example, in some embodiments of the invention, control circuitry 130 may send a control signal to user interface 120 to configure it to receive input from a user or give instructions to a user.

Processing circuitry 140 may include any type of circuitry, such as processors, microcontrollers, and connections designed to process data from distance measurement circuitry 110 , user interface 120 , and other components of system 100 , or any combination thereof. to interactively measure either one or both edges of the eye's clear vision range. Additionally, the processing circuitry 140 may be electronically coupled with other components of the system 100 , or any combination thereof. For example, in some embodiments of the invention, the processing circuitry 140 may send a signal to the control circuitry 130 to configure the user interface 120 or the distance measurement circuitry 110 .

Storage 150 may include one or more storage media, such as internal or external memory of any type, such as: HDD, SSD, RAM, ROM, EPROM, Flash EEPROM, flash memory card such as an SD card (i.e. Secure Digital) CF Card (i.e., Compact Flash), or any other type of memory suitable for the electronic device included in system 100 .

The communications circuit 160 may include any circuit suitable for connecting the electronic device included in the system 100 to a communications network and transmitting data using any suitable protocol such as, for example, Wi-Fi (e.g., 802.11 protocol), Bluetooth®. , cellular protocol (for example, GSM, GPRS, CDMA, EDGE, LTE) or any other communications protocol or any combination thereof.

FIG. 2 is a block diagram of an illustrative electronic device 200 for interactively measuring one or both edges of the eye's clear vision range in accordance with one embodiment of the invention.

Electronic device 200 may be very similar to the electronic device included in system 100 shown in FIG. 1 and share descriptions of the components of the latter. For example, electronic device 200 may also include storage 250 and communications circuitry 260 , which may be substantially similar to the respective components of the electronic device in system 100 ; storage 150 , and communications circuitry 160 , or others, or any combination thereof.

The distance measurement circuitry 210 may be similar to the distance measurement circuitry 110 and use any suitable technique or combination of techniques to measure the distance between a user's head 270 and the electronic device 200 .

The user interface 220 may be connected to the control circuits 230 and the processing circuits 240 . The user interface ( 120 ; 220 ) may be configured to provide instructions to a user by means of a visual instruction message (see 304 in FIG. 3 ), or an audio message, or other user interface method, or any combination of the above methods. Additionally, the user interface ( 120 ; 220 ) can be configured to receive user input by tapping or swiping a finger on the touch screen, or typing on a keyboard or keypad, issuing a voice command by speaking into a microphone, performing a gesture detected by a camera, perform a gesture detected by a gyroscope or others or any combination of any of the above.

The control circuitry 230 may be similar to the control circuitry 130 and the processing circuitry 240 may be similar to the processing circuitry 140 . The processing circuits 240 may use any suitable technique or combination of techniques to interactively measure one or both edges of the eye's clear vision range from distance measurements between a user's head or part thereof 270 and the electronic device 200. obtained from distance measurement circuitry 210 , and user input obtained from user interface 220 , both configured by signals from control circuitry 230 .

The control circuitry 230 may configure the user interface 220 to instruct the user to slowly bring the electronic device 200 closer to the user's head 270 , until the display 220 is barely readable due to said proximity, corresponding to the distance that coincides with a near point NP located on the near side of the range of clear vision. As another example, the user interface 220 may instruct the user to slowly bring the device 200 closer to the user's head 270 , until the display 220 can no longer be read due to such proximity, which corresponds to a distance beyond the range. clear vision.

Similarly, the user interface 220 may instruct the user to slowly move the electronic device 200 further away from the user's head 270 , until the touch screen 220 is barely readable due to its distance from the head, corresponding to a distance which coincides with the remote point FP located on the other side of the clear vision range. As yet another example, the user interface 220 may instruct the user to move the device 200 further away from the user's head 270 , until the screen 220 can no longer be read due to such separation, which corresponds to a further distance. beyond the range of clear vision.

Additionally, the control circuit 230 may instruct the user (or another) 220 to indicate such proximity or separation of the electronic device using the user interface 220 by touching the touch screen or by issuing a voice command to the voice recognition module, or another input method, or a combination of any of the above. The control circuitry 240 may then use this user input and the corresponding distance measurement between the user's head 270 and the electronic device 200 obtained from the distance measurement circuitry 210 to measure pNP or dNP, pFP or dFP. Additionally, the processing circuitry 240 may use any suitable technique or combination of techniques to calculate the SICV or both and additional information, such as the user's age, sex, eye to be examined or others, or any combination of the themselves.

In some embodiments, the processing circuitry 240 may automatically detect the age, gender, or eye of the user to be examined, or others, or any combination of any of the above parameters from an image of the user's head 270 of a camera included in distance measurement circuits 210 . In some embodiments, the processing circuitry 240 may obtain the age, sex, eye to be examined, previous refraction or addition or reading glasses power of said user, or any combination of the above by sending a signal to control circuitry 230 that configures the touch screen included in the user interface 220 to prompt the user to enter these parameters. In some embodiments, processing circuitry 240 may obtain said parameters by sending a signal to control circuitry 230 to configure storage 250 or communications circuitry 260 to retrieve said parameters from local or remote memory.

FIG. 3 is an exemplary view of an illustrative display of an electronic device 300 for interactively measuring one or both edges of the eye's clear vision range in accordance with an embodiment of the invention where a stimulus is displayed on a touch screen included in the user interface.

Electronic device 300 may be substantially similar to device 100 shown in FIG. 1 and the device 200 shown in FIG. 2 and share component descriptions with one or both. For example, the electronic device 300 may include a camera in the distance measurement circuit 310 and a touch screen in the user interface 320 . In some embodiments, the touch screen included in the user interface 320 may be configured to display a stimulus 330 to the user, including, but not limited to, the following types of stimuli; an optotype 330a , text 330b , a geometric pattern 330c, 330d , a gray discrimination stimulus 330e , a color discrimination stimulus 330f , a spatial geometric figure stimulus 330g , or an image or film 330h or any combination of any of the previous ones.

In some embodiments, the stimulus 330 or a component of the stimulus, including the foreground, background, or a portion of its shape, may be configured to change its size, shape, rotation, color, background color, or spatial frequency composition or other characteristics or any combination of any of the above based on the distance measured between the user's head 270 and the electronic device 300 , or based on another dimension measured on the user's head by the distance measurement circuit 210 , which changes proportionally with said distance, such as interpupillary distance, head width, iris diameter, or others, or any combination thereof.

In some embodiments, the stimulus 330 may be configured to change its characteristics depending on user input from the interface 320 . For example, the stimulus 330 may be configured to change size, shape, rotation, color, background color or other characteristics, or any combination of any of the above as a result of the user's interaction with the electronic device 300 using the display. touch 320 by swiping, clicking, voice command or other gesture, or any combination of any of the above. Additionally, in some embodiments, user interaction with user interface 320 may be performed using a keyboard, keyboard keypad, mouse, microphone or any other interface method, or any combination of any of the above.

FIG. 4 is a flowchart of an illustrative subprocess 400 for changing a stimulus with the distance between a head and an electronic device according to one embodiment of the invention. Thread 400 may consist of multiple steps. In some embodiments, the order of the steps of thread 400 may be changed or some steps may be skipped or repeated. Additionally, thread 400 can be included in another process (main process) as a thread.

Thread 400 may be realized by an electronic device ( 100 ; 200 ; 300 ) with distance measurement circuitry ( 110 ; 210 ; 310 ) and user interface ( 120 ; 220 ; 320 ), and one or more components of the electronic device. ( 100 ; 200 ; 300 ).

The first step of subprocess 400 may continue from a main process and begin with block 410 where the user interface ( 120 ; 220 ; 320 ) may be configured to display a stimulus 330 on a screen 320 . For example, in one embodiment of the invention, said stimulus may be an optotype 330a , or text 330b , or one or more parallel lines 330c , 330d , or one or more gray areas 330e or color areas 330f , or a geometric pattern such such as a grid 330g , or an image 330h , or another type of stimulus, or any combination of any of the above.

At block 420 , a user can change the distance between the user's head 270 and the electronic device ( 100 ; 200 ; 300 ). Additionally, the distance measurement circuitry ( 110 ; 210 ; 310 ) may send to the processing circuitry ( 140 ; 240 ) a signal including a distance measurement between the head of the user 270 and the electronic device ( 100 ; 200 ; 300 ). . As noted above, distance measurement circuits ( 110 ; 210 ; 310 ) may use any suitable technique or combination of techniques to measure the distance between a user's head 270 and the electronic device. Additionally, such distance between the user's head and the device can be measured using another method (such as a ruler or rangefinder) and input in the user interface ( 120 ; 220 ; 320 ).

In some embodiments of the present invention, changing the distance between the user's head 270 and the electronic device may comprise holding the device in the user's hand and moving it closer to the face or away from the face.

In some embodiments of the present invention, changing the distance between the user's head 270 and the electronic device may comprise placing a reflective surface, such as a mirror, in front of the electronic device (so that this reflection of the user's head 270 is within the field of view of the electronic device) and changing the distance between the device and a mirror, or the distance between said user's head or part of it 270 and a mirror, or any combination thereof.

In some embodiments of the present invention, changing the distance between the user's head 270 and the electronic device may comprise changing the distance by a third party, such as another person, another device, or another, or any combination of any of the above.

Block 430 may be a decision block in which the user interface ( 120; 220; 320 ) may be configured to instruct the user to evaluate whether a stimulus 330 or a component of the stimulus meets a certain visual quality criterion. For example, in one embodiment of the invention, said visual quality criterion may be a visual acuity criterion (for example, being able to read optotypes ( 330a ) or text ( 330b ), or resolving two or more parallel lines ( 330c, 330d ). , or other, or any combination of any of the above). As another example, in one embodiment of the invention, said visual quality criterion may be a contrast sensitivity criterion (for example, being able to distinguish gray spots ( 330e ) or match gray spots) or a color discrimination criterion ( for example, being able to distinguish colors ( 330f ) or combine colors), or a spatial geometry criterion (e.g., being able to detect deformations in geometric patterns ( 330g ) such as the deformation of a grid) or recognizing images or details in images ( 330h ), or other criteria, or any combination of any of the above.

Furthermore, said evaluation of whether a stimulus 330 or a stimulus component meets a certain visual quality criterion in block 430 may include the evaluation of: continuation, cessation or satisfaction of said visual quality criterion.

In one embodiment of the invention, at block 430 the user may be instructed to evaluate whether a stimulus or stimulus component has ceased to meet said visual quality criterion, for example, whether it has become blurred, distorted, discolored, poorly clear or another.

Additionally, in decision block 430 , if user input to the user interface ( 120; 220; 320 ) indicates that a stimulus 330 satisfies or fails to satisfy a certain visual quality criterion, thread 400 may proceed to the decision block 430. 440 . For example, the user may no longer see a fine spatial pattern in the stimulus at a certain distance as it moves away from the user's head and it becomes blurred, in which case thread 400 may proceed to block 440.

On the other hand, in decision block 430 if the user interface ( 120; 220; 320 ) does not indicate user input with respect to a certain visual quality criterion, process 400 may go to block 450 , which may be a decision block. At block 450 , if the distance between a user's head 270 and the electronic device cannot be changed further (for example, a user cannot move the electronic device further than arm's length), thread 400 may pass to block 440 .

At block 440 , the distance between a user's head 270 and the electronic device ( 100; 200; 300 ) may be stored in storage ( 150; 250 ) or transmitted via a communications circuit ( 160; 260 ) along with, but not limited to, user input data. Additionally, at block 440 , thread 400 may return to a parent process in which it may be included.

On the other hand, in block 450 , if said distance between a user's head 270 and the electronic device can be changed further, thread 400 can move to block 460.

At block 460 , the user interface may be configured to change the characteristics of a stimulus 330 or a component of the stimulus. For example, in one embodiment of the invention, the distance measurement circuit ( 110; 210; 310 ) can send to the processing circuit ( 140; 240 ) a signal that includes a distance measurement between the head 270 of a user and the electronic device ( 100; 200; 300 ). The processing circuit may use any technique or combination of techniques to process said signal and send a signal to the control circuit ( 130; 230 ), which in turn may configure the user interface ( 120; 220; 320 ) to change such characteristics of the stimulus 330 or a component of the stimulus such as size, shape, rotation, color, background color or spatial frequency composition or other characteristics, or any combination of any of the above, based on said distance between the head of a user 270 and electronic device, or based on another dimension measured on the user's head by the distance measurement circuitry 210, which changes proportionally with said distance, such as interpupillary distance, head width, iris diameter, or others, or any combination thereof.

FIG. 5 is a flow chart of an illustrative process 500 for interactively measuring one or both edges of the eye's clear vision range in accordance with one embodiment of the invention. The process 500 may consist of several steps. In some embodiments, the order of the steps of process 500 may be changed or some steps may be skipped or repeated.

The process 500 may be performed by an electronic device ( 100; 200; 300 ) with distance measurement circuitry ( 110; 210; 310 ) and user interface ( 120; 220; 320 ), and one or more components of the electronic device ( 100; 200; 300 ).

The process 500 may begin at block 510 where a user interface ( 120 ; 220 ; 320 ) of an electronic device ( 100 ; 200 ; 300 ) may be configured to receive input information from the user, such as age, gender, value of spherical-cylindrical power of the ophthalmic or contact lenses already worn by the subject, vertex distance, or others or any combination thereof. For example, in one embodiment of the invention, said information can be acquired by configuring the user interface ( 120 ; 220 ; 320 ) to request the user to enter said information into the user interface using a touch screen or a recognition circuit. voice, or other, or any combination of them. As another example, in one embodiment of the invention said information can be acquired automatically by detecting it from an image of the head of a user 270 of a camera included in said user interface.

At block 520 , the user interface ( 120 ; 220 ; 320 ) may be configured to instruct the user to use one eye (left or right) or both eyes while interacting with the electronic device ( 100 ;

200 ; 300 ).

At block 530 , process 500 may include thread 400 (see FIG. 4 ). For example, in one embodiment of the invention, in decision block 430 of thread 400 included in block 520 of process 500 , a user may provide user input to the user interface ( 120 ; 220 ; 320 ) indicating that The visual quality of a stimulus 330 meets a certain criterion corresponding to an electronic device ( 100 ; 200 ; 300 ) being located on either side of the SICV clear vision interval. In block 440 (see FIG. 4 ) of thread 400 included in block 530 of process 500 , the distance between an electronic device ( 100 ; 200 ; 300 ) and the head of a subject 270 may be stored in storage ( 150 ; 250 ) or transmit using communications circuits ( 160; 260 ).

At block 540 , the user interface ( 120 ; 220 ; 320 ) may be configured to display a new stimulus and prompt the user to select a preferred angle of orientation of the stimulus while interacting with the electronic device ( 100 ; 200 ; 300 ). . As an example, in one embodiment of the invention, the user interface ( 120 ; 220 ; 320 ) of an electronic device ( 100 ; 200 ; 300 ) located in the vicinity of dFP or pNP (which are the two outer points) can be configure to receive user input that includes a preferred angle of orientation of the adFP or apNP stimulus. In one embodiment of the invention, the user interface ( 120 ; 220 ; 320 ) can be configured to change a stimulus 330 or a component of the stimulus on a touch screen 320 in response to user input, such as touching or swiping a screen. touch, or typing on a keyboard or keypad, speaking into a microphone, performing a gesture detected by a camera, performing a gesture detected by a gyroscope, or others or any combination of any of the above. As a further example, in one embodiment of the invention, the user interface ( 120 ; 220 ; 320 ) can be configured to display a stimulus 330 that includes, but is not limited to, a set of parallel or concentric lines on a screen. touch screen 320 , and to receive user input from said touch screen 320 and change the orientation of said stimulus 320 in the adFP or apNP angle.

At block 550 , a preferred angle of orientation of the adFP stimulus selected by a user at block 540 may be stored in storage ( 150 ; 250 ) or transmitted using a communications circuit ( 160;260 ).

At block 560 , process 500 may include thread 400 (see FIG. 4 ). At block 410 , the user interface ( 120 ; 220 ; 320 ) may be configured to display a new stimulus 330 including, but not limited to, a set of parallel or concentric lines on a touch screen 320 oriented at an adFP or apNP angle. .

As described above, in decision block 430 of thread 400 included in block 560 of process 500 , a user may provide user input to the user interface ( 120 ; 220 ; 320 ) indicating that the visual quality of said stimulus 330 or a component of the stimulus satisfies or fails to satisfy a certain visual quality criterion corresponding to an electronic device ( 100 ; 200 ; 300 ) that is located on both edges of the interval of clear vision, at a distance close to dFP or pNP . In block 440 of thread 400 , said distance may be stored in storage ( 150 ; 250 ) or transmitted using communications circuits ( 160;260 ).

At block 570 , process 500 may include thread 400 (see FIG. 4 ). At block 410 , the user interface ( 120 ; 220 ; 320 ) can be configured to display a new stimulus 330 including, among others, a set of parallel lines on a touch screen 320 oriented at an angle apFP = adFP 90° or adNP = apNP - 90°.

As described above, in decision block 430 of thread 400 included in block 570 of process 500 , a user may provide user input to the user interface ( 120 ; 220 ; 320 ) indicating that the visual quality of said stimulus 330 or a component of the stimulus meets or fails to meet said visual quality criterion, corresponding to an electronic device ( 100; 200; 300 ) located on either side of the clear vision interval, at a distance close to pFP or dNP (which are the two internal points). At thread block 440 , said distance can be stored in storage ( 150 ; 250 ) or transmitted using communications circuits ( 160;260 ).

At block 580 , the processing circuits ( 140 ; 240 ) may use any technique or combination of techniques to calculate ocular refractive errors such as, but not limited to, sphere (SPH), cylinder (CYL) and axis (AXS) of dFP, pFP, adFP apFP, dNP, pNP, adNP or apNP or others, or any combination of any of the above.

In one embodiment of the invention, AXS can be calculated from dFP and pFP using, for example, the following equations:

AXS = 90° - apFP if 0° < adFP < 90°; either

AXS = 270°- adFP otherwise; Eq. 1

and adFP = apFP - 90°.

Additionally, AXS can be calculated from dNP and pNP using, for example, the following equations:

AXS = 90° - adNP if adNP < 90°; either

AXS = 270°- adNP otherwise; Eq. 3

and adNP = apNP - 90°. Eq. 4

where adNP, apNP, adFP, and apFP are expressed in units of degrees from 1° to 180°.

SPH and CYL can be calculated from dFP, pFP using, for example, the following equations:

SPH = - 1/dFP K. Eq. 5

CYL = -(1/pFP -1/dFP), Eq. 6

where the parameter K depends on the background color and the stimulus. In the case of a black background, K = 0 D, K > 0 D and K < 0 D for whites, blues and reds, respectively. The specific value of K depends on an emission spectrum of a physical stimulus.

In one embodiment of the invention, SPH and CYL can also be calculated from dNP, pNP using, for example, the following equations:

SPH = AA - 1/dNP K. Eq. 7 CYL = -(1/pNP -1/dNP), Eq. 8

The values of dFP, pFP, dNP, pNP can be expressed in meters and K in diopters. The AA value, expressed in diopters, may depend on age (AGE), expressed in years, such as:

AA = 15.6 - 0.3 * AGE when AGE <= 52 years; or Eq. 9

AA = 0 D otherwise.

Additionally, at block 580 , the processing circuitry ( 140 ; 240 ) may use any technique or combination of techniques to calculate the power of the reading glasses (P) from dNP or pNP, or other parameters, or any combination thereof. For example, in one embodiment of the invention, the power of the reading glasses P can be calculated as:

P = 3 D - E (1 / ((dNP pNP)/2) K), when E(1 / ((dNP pNP)/2) K) < 3D

P = 0 D otherwise. Eq. 10

where P can be expressed in diopters and E can be a constant value between 0 and 1.

As described above, in block 520 of process 500 , the user interface ( 120 ; 220 ;

320 ) can be configured to instruct the user to use one eye (left or right) or both eyes while interacting with the electronic device ( 100 ; 200 ; 300 ). As an example, in an embodiment of The invention, in block 410 (see FIG. 4 ) of thread 400 included in block 530 of process 500 , the user interface ( 120 ; 220 ; 320 ) may be configured to display a stimulus 330 including, but not limited to , a text ( 330b ). In block 440 of thread 400 , a near point distance NP ( 150 ; 250 ) can be stored and the power P of the reading glasses can be calculated as:

P = 3 D - E(1 / NP K), when E(1 / NP K) < 3 D

P = 0 D otherwise. Eq. eleven

where NP can be expressed in meters.

In one embodiment of the invention, the reading glasses addition (ADD) can be calculated using the following equations:

ADD = P -(SPH CYL/2) if P > (SPH CYL/2); either

ADD = 0 D otherwise. Eq. 12

Eq. 1-12 correspond to the refraction of the corneal plane.

Furthermore, in block 580 of process 500 , processing circuits ( 140 ; 240 ) included in an electronic device ( 100 ; 200 ; 300 ) may use any suitable technique or combination of techniques to calculate the refraction of the plane of the glasses or the reading glasses power of the corneal plane refraction of dNP, pFP, dNP, pNP, FP, NP, vertex distance (DV) or others, or any combination thereof. The DV depends on the type of correction (typically 0.0 m for contact lenses and 0.014 m for glasses).

In block 590 parameters such as, but not limited to, SPH, CYL, AXS, FP, NP, P, ADD, dFP, pFP, a dFP, a pFP, dNP, pNP, a dNP, a pNP, DV, user input, or others, or any combination of any of the above can be stored in storage ( 150 ; 250 ).

Claims (17)

1. A computer-implemented method for interactively measuring one or both edges of the clear vision range of a user's eye using an electronic device comprising: • displaying at least one stimulus (330a-330h) on an electronic screen (320) of the electronic device (300); • change the vergence of the light rays that originate from said stimulus (330a-330h) and reach the user's head (270); • receiving information from the user indicating that the electronic device (300) is placed at a distance from the user's head (270) or part thereof, where the visual quality of said stimulus (330a-330h) or a component of the stimulus, satisfies or fails to satisfy a certain visual quality criterion; • calculate at least one position of at least one of the edges of the clear vision interval based on at least said distance. 2. The computer-implemented method of claim 1, wherein displaying a stimulus on an electronic screen (320) of the electronic device (300) comprises changing, independently of the distance from the user's head, at least one characteristic of said stimulus (330a-330h) or a component of said stimulus (330a-330h), where said characteristic is chosen, at least, from among the following: size, orientation, position, color, spatial frequency, and/or a combination of the above. 3. The computer-implemented method according to claim 2, wherein said stimulus (330a-330h) displayed on an electronic screen (320) of the electronic device (300) comprises: • a single letter, optotype or a group thereof, • a text, • a geometric shape, • a color or grayscale drawing, • a repetitive drawing, • an image or film, • or any combination of any of the above. 4. The computer-implemented method according to any one of the preceding claims 1 to 3, wherein calculating at least one position of at least one of the edges of the clear vision range comprises: • changing the characteristics of said stimulus or a component of the stimulus on the electronic display (320) to satisfy or fail to satisfy said visual quality criterion according to the orientation angle of the stimulus preferred by the user; • measuring a first distance between the electronic screen (320) and the user's head (270) or part thereof; • changing a stimulus (330a-330h) to include at least one straight or curved line oriented perpendicular to said preferred angle of stimulus orientation; and • measuring a second distance between said electronic screen and the user's head. 5. The computer-implemented method according to claims 1 and 4, wherein said preferred stimulus orientation angle is found by physically rotating the screen or stimuli on the electronic display (320) of the electronic device (300) around the line main point of view of the user. 6. The computer-implemented method according to claims 1 and 4, wherein said preferred stimulus orientation angle is calculated from an image of the user's head or part thereof rotating with respect to the electronic display. (320) of the electronic device (300). 7. The computer-implemented method according to claim 4, wherein the first distance is calculated from a mathematical relationship between the age of the user and the second distance. 8. The computer-implemented method according to any one of claims 1 to 7, further comprising placing a reflective surface between a user's eye or a user's head (270) or part thereof and said electronic display (320). ) of the electronic device (300) to change the vergence of the rays that travel from said stimulus (330a-330h) to said head of the user (270). 9. The computer-implemented method according to any one of claims 1 to 8, further comprising calculating at least one of the following refraction parameters: sphere, SPH, cylinder, CYL, axis, AXS, glasses power reading, P, or addition, ADD; where the refraction parameter is calculated from a mathematical relationship between said parameter and the vertex distance, VD, from the corneal plane to the plane of the glasses lens, or vice versa. 10. The computer-implemented method according to any one of claims 1 to 9, wherein said age of the user, AGE, is obtained by one of the following methods: • entering the AGE or date of birth into a user interface by the user or remotely from a database on the electronic device, • detecting AGE from an image of the user's head or part of it using an age detection algorithm; • any combination thereof. 11. A non-transitory storage medium comprising instructions executable by one or more processors for carrying out the method for interactively measuring one or both edges of the range of clear vision of a user's eye by means of an electronic device according to any one of claims previous 1 to 10. 12. System for interactively measuring one or both edges of the clear vision range of a user's eye using an electronic device (300) comprising: • a distance measuring circuit (210) configured to detect a distance between the user's head or part thereof and the electronic device (300); • a user interface (120) configured to give instructions to the user and receive information from the user; • an electronic display (320) for displaying and changing a stimulus; • a processing circuit (240) for calculating the position of at least one of the edges of the clear vision interval. 13. The system according to claim 12, wherein the processing circuit (240) of the electronic device can be further configured to: • calculate at least one selected refraction parameter of sphere, cylinder, axis, reading glasses power, or addition, from the position of one or both edges of the range of clear vision, age of the user, chromatic or spatial characteristics of said stimulus, stimulus orientation angle indicated by the user, or any combination thereof; • calculate the amplitude of accommodation, based on the position of one or both edges of the clear vision interval, the age of the user, the chromatic or spatial characteristics of said stimulus, the orientation angle of the stimulus indicated by the user or other parameters , or any combination thereof. 14. The system according to claim 11, wherein the distance measurement circuit and the user interface of the electronic device can be further configured to: • measuring a rotation of the device with respect to an axis such as, but not limited to, a line of sight between the user and said electronic device; • measure a rotation or inclination of the user's head or part of it with respect to said axis. 15. The system according to any of claims 11-13, wherein the user interface further comprises: • a speaker, • a microphone, • voice recognition circuits, • gesture recognition circuits, • or any combination thereof. 16. An electronic device (300) comprising the system according to any of claims 12 to 14, wherein the electronic device (300) is one of the following: • a Mobile phone; • a tablet; • a smart television; • a personal digital assistant; • a laptop; • a desktop computer; • a separate camera; • a games console; • a video recorder. 17. An electronic device according to claim 16 further comprising: • a memory of the electronic device configured to store said parameters; • a communications circuit (160, 260) configured to transmit said parameters to and from a network.