Methods and systems for assessing human visual acuity

Abstract

A method for assessing a person's visual acuity using a mobile device, the mobile device including at least one front-facing camera and a screen, the method comprising: - a user positioning step, during which a user of the mobile device positions themselves in front of a mirror at a predefined distance d / 2; - a mobile device positioning step, during which the mobile device is positioned such that the front-facing camera of the mobile device faces the mirror; - a distance measurement step, during which a distance d between the front-facing camera of the mobile device and a virtual image of the mobile device in the mirror is measured; - a display step, during which the screen of the mobile device displays optometry text; - an assessment step, during which the user's visual acuity is assessed.

Description

Technical Field

[0001] This disclosure relates to the assessment of human visual acuity. In particular, this disclosure relates to a method for assessing human visual acuity using a mobile device. This disclosure further relates to a mobile device for measuring human visual acuity.

[0002] Furthermore, this disclosure relates to a display system for determining a person's visual acuity. Background Technology

[0003] Typically, a person's uncorrected or corrected visual acuity is assessed by an eye care professional. This assessment requires an appointment with an ophthalmologist, making it difficult to check a person's visual acuity regularly and frequently.

[0004] Existing technological methods have been developed to create solutions for checking visual acuity without the need for intervention from eye care professionals.

[0005] However, these methods typically require a laptop computer, making them inaccessible to some users. Furthermore, most existing methods require a calibration procedure, such as using a credit card or shoe size, to determine and set the distance between the laptop and the user before the procedure used to measure visual acuity. Therefore, the lack of proper distance control during the procedure can lead to errors in visual acuity measurement.

[0006] Some existing technological approaches propose self-measurement solutions, such as those using smartphone apps. However, the measurement is performed at arm's length while the user holds the smartphone, which limits the assessment of visual acuity to near vision. Other smartphone apps, generally proposed for professional use, allow the measurement of a person's visual acuity in terms of distance vision, but require the intervention of a second person (usually an eye care professional).

[0007] Therefore, a simple, fast, and accurate solution for assessing a person's visual acuity is needed. Summary of the Invention

[0008] Therefore, this disclosure proposes a method for assessing human visual acuity using a mobile device, the mobile device including at least one front-facing camera and a screen, the method comprising:

[0009] - User positioning step, during which the user of the mobile device positions themselves at a predefined distance d / 2 in front of the mirror;

[0010] - Mobile device positioning step, during which the mobile device is positioned so that the front camera of the mobile device is facing the mirror;

[0011] - Distance measurement step, during which the distance d between the mobile device's front camera and the virtual image of the mobile device in the mirror is measured;

[0012] - Display steps, during which the mobile device's screen displays the word "refraction"; and

[0013] - Evaluation step, during which the user's visual acuity is evaluated.

[0014] Advantageously, the method according to this disclosure allows for easy and accurate assessment of human visual acuity.

[0015] Advantageously, the assessment according to this method can be performed by the user at home. Then, an optometrist in a remote location can check whether the test has been performed accurately.

[0016] Users no longer need to travel to professional eye care centers for visual acuity assessments. This is more convenient for users, as there are no longer transportation or time restrictions for the assessment.

[0017] According to further embodiments that can be considered individually or in combination:

[0018] - During the mobile device positioning step, the mobile device is vertically positioned to cover one of the user's eyes; and / or

[0019] - During the assessment steps, measure the user's binocular visual acuity, and / or

[0020] - During the assessment steps, measure the user's monocular visual acuity, and / or

[0021] The method further includes a distance control step prior to the display step, during which the measured distance d is compared with the predefined distance d / 2; and / or

[0022] The method further includes a notification step, during which a notification is sent to the user based on a comparison of the measured distance d with the predefined distance d / 2; and / or

[0023] - When the measured distance d is less than or equal to 2×(d / 2)-Δ1, the notification indicates that the person is too close to the mirror; and / or

[0024] - When the measured distance d is greater than or equal to 2×(d / 2)+Δ2, the notification indicates that the person is too far from the mirror; and / or

[0025] - Adjust the size of the optometry font displayed during the display step based on the measured distance d; and / or

[0026] - Adjust the angular size of the optometry font displayed during the display step based on the measured distance d; and / or

[0027] - During the display and evaluation steps, periodically measure the distance d / 2 between the front camera and the mirror, and during the display step, adjust the size and / or angle of the displayed optometric font in real time based on the measured distance d / 2; and / or

[0028] The method further includes a mobile device data receiving step, during which mobile device data is received, the mobile device data including at least screen data related to at least the physical size of the mobile device's screen and at least camera data related to at least the angular resolution of the pixels of the front-facing camera, and the distance d is measured at least based on the mobile device data; and / or

[0029] The method further includes a camera data receiving step, during which the front-facing camera of the mobile device acquires scene data, and the distance d is measured at least based on the camera data; and / or

[0030] - A predefined distance d / 2 is greater than or equal to 1.5m, preferably greater than or equal to 2.0m, and visual acuity is assessed under distance vision conditions; and / or

[0031] - A predefined distance d / 2 is less than or equal to 0.5m, preferably less than or equal to 0.25m, and visual acuity is assessed under near vision conditions; and / or

[0032] - The method further includes an input receiving step, during which an instruction is received from the user in response to the displayed optometric font, and the user's visual acuity is assessed based on the instruction received from the user; and / or

[0033] - The optometric font displayed on the mobile device screen during the display step includes a single Landolt-C target with different orientations / orientations, and the indication received from the user is related to the notch orientation / orientation of the Landolt-C target as perceived by the user; and / or

[0034] - The perceived direction of the gap in the Landau Ring sight is indicated by the user using voice recognition and / or gesture recognition and / or movement of the mobile device; and / or

[0035] - The displayed optometry text further includes a movable cursor, and the perceived direction of the Landau ring target on the mobile device's screen is indicated by the position of the movable cursor; and / or

[0036] - The mobile device includes physical volume up and volume down buttons, and a movable cursor is controlled by a person using the physical volume up and volume down buttons of the mobile device; and / or

[0037] - Mobile devices can be held with one hand, such as smartphones, phablets, or tablets.

[0038] This disclosure further relates to a computer-readable storage medium having a program recorded thereon, wherein the program causes a computer to perform the method according to this disclosure.

[0039] This disclosure also relates to a computer-readable, non-transitory program storage device that tangibly embodies a program having instructions executable by a computer to perform methods including the following operations:

[0040] -Measure the distance d between the front-facing camera of the mobile device and the mirror facing the front-facing camera of the mobile device;

[0041] - Display the optometry text on the screen of your mobile device;

[0042] - Receive input from users on mobile devices, and

[0043] - Assess the user's visual acuity based on the received input.

[0044] This disclosure further relates to a mobile device, including:

[0045] -Screen;

[0046] -At least one front-facing camera;

[0047] - A memory configured to store instruction sequences; and

[0048] - A processor coupled to the memory, the screen, and the at least one camera.

[0049] The processor is configured to execute a sequence of instructions to perform the following operations:

[0050] - Measure the distance d between the front-facing camera and the mirror facing the front-facing camera;

[0051] - Display the optometry text on the screen of your mobile device;

[0052] - Receiving input from users on mobile devices; and

[0053] - Assess the user's visual acuity based on the received input.

[0054] Furthermore, this disclosure relates to a display system for determining a person's visual acuity, the display system comprising:

[0055] - A control device for identifying and processing input data received from a person;

[0056] - A display device for displaying at least one optometry font and at least one movable cursor, the optometry font being oriented in a direction selected from a predefined orientation list, and the movable cursor being configured to be displayed in any direction from the predefined orientation list, the orientation of the displayed movable cursor being based on input processed by a control device.

[0057] Advantageously, this display system provides a simple and easy-to-use way to implement a method for assessing a person's visual acuity.

[0058] The mobile device system may include a display system. The display device may be formed by the screen of the mobile device. The mobile device may further include a control device for the display system, the control device being configured to identify and process input data received from a person. Attached Figure Description

[0059] Embodiments of the invention will now be described by way of example only and with reference to the following accompanying drawings, in which:

[0060] - Figure 1 A flowchart illustrating an embodiment of a method for assessing human visual acuity using mobile devices;

[0061] - Figure 2 A person whose visual acuity is measured according to an embodiment of this disclosure is shown;

[0062] - Figure 3a and Figure 3b A person whose visual acuity is measured according to an embodiment of this disclosure is shown;

[0063] - Figure 4 Examples of mobile devices according to embodiments of the present disclosure are shown;

[0064] - Figure 5 A person is shown measuring their visual acuity according to an embodiment of this disclosure; and

[0065] - Figure 6 A display system for determining a person's visual acuity according to an embodiment of the present disclosure is shown.

[0066] The elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be enlarged relative to other elements to aid in understanding embodiments of the invention. Detailed Implementation

[0067] This disclosure relates to a method for assessing a person's visual acuity using a mobile device 2. Visual acuity generally refers to visual clarity, but technically, it is an assessment of a person's ability to accurately identify small details. Visual acuity can be assessed for users wearing or not wearing glasses.

[0068] In the context of this invention, a mobile device is a portable computer device that can be used independently and is small enough to be easily carried and operated by a user. For example, a mobile device can be a smartphone, a phablet, or a tablet computer.

[0069] For clarity and simplicity, smartphones will be used as the mobile device in the following disclosure. However, those skilled in the art will be able to readily adapt the following examples to any other mobile device as defined in this disclosure.

[0070] like Figure 4 As shown, the mobile device 2 includes at least one screen 4 and a front-facing camera 6. The screen 4 and the front-facing camera 6 are positioned on the same side of the mobile device 2.

[0071] The mobile device 2 further includes a memory 8 and a processor 12, the memory being configured to store a sequence of instructions, and the processor being coupled to the memory 10 and configured to execute the sequence of instructions stored in the memory 10.

[0072] like Figure 1 As shown, the method for assessing a person's visual acuity includes a user positioning step S2. During user positioning step S2, the user of the mobile device positions themselves in front of a mirror at a predefined distance d / 2 from the mirror.

[0073] like Figure 2 As shown in Figure 3, the user positions themselves at a predefined distance d / 2 facing mirror 20 to see a virtual image generated by light reflected from the mirror surface. Preferably, mirror 20 is a plane mirror. When the user is at the predefined distance d / 2, the distance between the user and the virtual image seen in the mirror can be defined as twice the predefined distance d / 2.

[0074] According to embodiments of the invention, the predefined distance d / 2 is greater than or equal to 1.5 m, preferably greater than or equal to 2.0 m. Advantageously, the predefined distance d / 2 is greater than or equal to 2.5 m to better relax accommodation. Under this condition, the method of this disclosure assesses the visual acuity of a user for distance vision.

[0075] Alternatively, the predefined distance d / 2 can be less than or equal to 0.5m, and preferably greater than or equal to 0.25m. Under these conditions, the method of this disclosure is for assessing the visual acuity of users with near vision.

[0076] like Figure 1 As shown, the method for assessing a person's visual acuity further includes a mobile device positioning step S4. During the mobile device positioning step S4, the user positions the mobile device 2 so that the front-facing camera 6 faces the mirror.

[0077] like Figure 2 As shown in Figure 3, the user positions the mobile device 2 with the front-facing camera 6 facing the mirror 20. Preferably, the mobile device 2 is vertically positioned substantially parallel to the plane of the mirror 20. More preferably, the mobile device 2 is positioned as close as possible to the user's head.

[0078] According to embodiments of this disclosure, the mobile device 2 is vertically positioned to cover one of the user's eyes, and the visual acuity of the other eye is assessed. Advantageously, having the mobile device cover the user's eye allows for convenient assessment of the monocular visual acuity of the user's uncovered eye.

[0079] like Figure 1 As shown, the method for assessing a person's visual acuity further includes a distance measurement step S8. During the distance measurement step S8, the distance d between the front-facing camera of the mobile device and the virtual image of the mobile device is measured.

[0080] The distance d between the front-facing camera of mobile device 2 and the virtual image 2' generated by the mirror 20 reflecting the mobile device can be measured using mobile device 2 itself.

[0081] according to Figure 1 The embodiments of this disclosure shown include a method for assessing human visual acuity that may include a mobile device data receiving step S0, during which mobile device data is received. The mobile device data includes at least screen data relating to at least the physical size of the mobile device's screen and at least camera data relating to at least the angular resolution of the pixels of a front-facing camera.

[0082] Screen data enables the adjustment of the display of optometry fonts based on the physical size of the mobile device screen, and more specifically, the adjustment of the positioning and size of the optometry fonts.

[0083] During the distance measurement step S8, the screen data enables the determination of the size of the element to be displayed, which has a known size.

[0084] In this embodiment, the element displayed during the distance measurement step is an optometric font.

[0085] like Figure 4 As shown, the physical size of the screen is represented by w. s ×h s , where w s Where h is the width of the physical screen. s The height of the physical screen, which can be based on the screen's resolution in meters. s ×n s and the pixel density of the screen D p,s(Measured in dots per inch or dpi) from any mobile device². Screen resolution and pixel density can be easily obtained from the mobile device's operating system (OS) or from manufacturer data.

[0086] Given m s n s and D p.s The value of w can be determined using the following equation. s and h s Value:

[0087]

[0088] By providing a non-restrictive example, for screen resolution m s ×n s Equal to 1440×3040 and pixel density D p,s The calculation of the physical screen size of mobile device 2 is illustrated using a specific smartphone S with a resolution of 550 dpi. Using equation (1), the physical screen width ws is obtained to be 66.5 mm and the physical screen height is 140.4 mm.

[0089] Alternatively, the physical screen size can be calculated using the screen's diagonal physical size and resolution.

[0090] angular resolution p of front camera pixels c,θ You can check the pixel size of the front camera (p) c (in meters) and focal length f c Similarly, the pixel size and focal length of the front-facing camera can be obtained from the mobile device's operating system (OS) or from manufacturer data.

[0091] Given p c and f c The value of p can be determined using the following equation. c,θ :

[0092]

[0093] During the distance measurement step S8, the display of an element with a known size on the screen of a mobile device with a front-facing camera facing a mirror makes it possible to evaluate the distance d based on the angular resolution of the front-facing camera.

[0094] In this embodiment, the element displayed during the distance measurement step is an optometric font.

[0095] By way of non-limiting example, for the pixel size p of the front-facing camera cThe calculation of the angular resolution of the front-facing camera pixels of mobile device 2 is illustrated using a specific smartphone S with a pixel size of 1.22 μm and a focal length of 3.34 mm. Using equation (2), the angular resolution p of the front-facing camera pixels is obtained. c,θ It equals 0.021°.

[0096] For simplicity, the camera's pixel physical size is p. c It is assumed to have the same value in both the horizontal and vertical directions. However, this reasoning can be easily extended if this condition is not true. For better accuracy, the value f can be replaced with the actual distance between the mobile device's lens and the camera sensor. c This is because the specified working distance of the front-facing camera may not be set to infinity. However, the inventors have observed that equation (2) produces sufficient accuracy. Alternatively, the actual distance between the lens and the camera sensor can be calculated by assuming the camera is set to a finite distance between 0.5m and 1.0m, preferably 0.8m.

[0097] The distance d between the front-facing camera of mobile device 2 and the virtual image generated by the mirror 20 reflecting the mobile device can be measured based on mobile device data and data received by the front-facing camera 6 of mobile device 2. Advantageously, the distance measurement according to this disclosure does not require a calibration step.

[0098] Advantageously, evaluating the distance d in the distance measurement step S8 based on mobile device data and the size of the element to be displayed on the screen of the mobile device during the distance measurement step S8 makes it possible to avoid the need for a distance calibration step.

[0099] The calibration step, which first displays the elements shown on the mobile device screen at a known distance from the mirror, is no longer required. Alternatively, it is no longer necessary to use an object other than the mobile device (such as a credit card) to calibrate the mobile device screen.

[0100] The distance d between the front camera and the virtual image of the element is directly measured based on the known size of the element displayed on the screen and mobile device data.

[0101] In an embodiment, given that the width of the mobile device screen is known and the size of the displayed optometric font is adjusted based on the width of the mobile device screen, the distance d can be continuously evaluated during the visual acuity assessment method.

[0102] In this embodiment, because the size of the displayed optometric font and the mobile device data are known, distance d can be continuously evaluated during the visual acuity assessment method when the optometric font is displayed on the screen. For example, the optometric font size can be defined based on the width of the mobile device screen.

[0103] In this embodiment, the accuracy and / or robustness of image processing are improved when the internal parameters of the mobile device that determine the mobile device data are known.

[0104] Therefore, the method for assessing human visual acuity can further include a camera data receiving step S6, during which the front-facing camera 6 of the mobile device 2 acquires data related to the scene it faces. Typically, the front-facing camera 6 of the mobile device 2 captures images and / or videos of the scene, particularly images and / or videos of mirrors and virtual images formed by mirrors facing the front-facing camera. The images and / or videos can be further processed to extract data related to the size of the virtual image of the mobile device screen reflected by the mirrors. For example, the screen width of the virtual mobile device reflected by the mirrors can be represented as the number of pixels m on the image / video recorded by the front-facing camera. c,d Similarly, the screen height of a virtual mobile device reflected by a mirror can be represented as the number of pixels n on the image / video recorded by the front-facing camera. c,d .

[0105] The distance d between the front-facing camera of mobile device 2 and the virtual image generated by mirror 20 can be determined using the following equation:

[0106]

[0107] then:

[0108]

[0109] Alternatively, the distance d can be measured by displaying different shapes with predefined known dimensions on the screen 4 of the mobile device 2. Given the dimensions of the displayed shapes, the distance d can be measured using equations (2) through (4).

[0110] The method for assessing human visual acuity may further include a parallelism measurement step, during which the parallelism of the mobile device 2 relative to the mirror 20 is measured. When the mirror is vertical, the parallelism of the mobile device can be measured using the mobile device's IMU. Alternatively, the parallelism of the mobile device 2 can be measured by displaying a predefined shape (e.g., a rectangle) on the screen 4 of the mobile device 2 and comparing the displayed shape with the shape of a virtual image generated by the mirror 20. For example, when the mobile device 2 is not parallel to the mirror 20, the rectangle displayed on the screen and reflected by the mirror 20 will produce a trapezoidal shape.

[0111] like Figure 1As shown, the method for assessing a person's visual acuity may further include a distance control step S10. During the distance control step, the measured distance d between the front-facing camera of the mobile device 2 and the virtual image generated by the mirror 20 is compared with a predefined distance d / 2.

[0112] Similarly, a method for assessing a person’s visual acuity may further include a parallelism control step, during which the shape of the virtual image generated by the mirror 20 is compared with a predefined shape displayed by the screen 4.

[0113] The method for assessing a person's visual acuity may further include a notification step S12. During the notification step, a notification is sent to the user based on a comparison of the measured distance d with a predefined distance d / 2.

[0114] For example, when the measured distance d between the front-facing camera of mobile device 2 and the virtual image generated by mirror 20 is less than twice the predefined distance d / 2, a notification can indicate that the user is too close to the mirror. Additionally, a deviation Δ1 can be considered. Deviation Δ1 represents the tolerance value of the predefined distance d / 2. When the measured distance d is less than (2 × (d / 2) - Δ1), a notification can indicate that the user is too close to the mirror. For example, deviation Δ1 can correspond to a change of 20%, preferably 10%, of the predefined distance d / 2.

[0115] For example, when the measured distance d between the front-facing camera of mobile device 2 and the virtual image generated by mirror 20 is greater than twice the predefined distance d / 2, a notification can indicate that the user is too far from the mirror. Additionally, a deviation Δ2 can be considered. Deviation Δ2 represents the tolerance value of the predefined distance d / 2. When the measured distance d is less than (2×(d / 2)+Δ2), a notification can indicate that the user is too close to the mirror. For example, deviation Δ2 can correspond to a change of 20%, preferably 10%, of the predefined distance d / 2.

[0116] Alternatively, a maximum deviation ΔD from a predefined distance value d / 2 can be defined. When the measured distance d is less than (2×(d / 2)-ΔD), a notification can indicate that the user is too close to the mirror. Similarly, when the measured distance d is greater than (2×(d / 2)+ΔD), a notification can indicate that the user is too far away from the mirror. The maximum deviation ΔD can correspond to a variation of 20%, preferably 10%, of the predefined distance d / 2.

[0117] Additionally, during notification step S12, a notification can be sent to the user based on a comparison between the shape of the virtual image generated by mirror 20 and a predefined shape displayed on screen 4. For example, when the difference between the compared shapes is too large (e.g., a 10% change), the notification can indicate that the mobile device 2 is not parallel to mirror 20.

[0118] like Figure 1 As shown, the method for assessing a person's visual acuity further includes a display step S14. Preferably, the display step is performed after the distance control step and the notification step. During the display step, optometry fonts are displayed on the screen 4 of the mobile device 2. In the sense of this disclosure, optometry fonts refer to standardized symbols commonly used for testing a person's vision.

[0119] like Figure 2 and Figure 3b As shown, the optometry font displayed on the screen 4 of the mobile device 2 is reflected on a mirror that generates a virtual image of the optometry font. Preferably, a symmetry transformation is applied to the displayed optometry font. Advantageously, the user will perceive the virtual image of the displayed optometry font in the correct orientation.

[0120] The displayed optometry font can be the Landolt C or Snellen E optometry font, or any other standardized optometry font, letter, or graphic. During the display step, the optometry fonts can be displayed one by one on the mobile device's screen 4. Alternatively, the optometry fonts can be displayed line by line, with multiple fonts per line. During the display step, the size and / or orientation and / or contrast of each optometry font can vary. Alternatively, multiple lines of optometry fonts can be displayed simultaneously, each line displaying optometry fonts of different sizes and / or orientations and / or contrasts, such as an ETDRS visual acuity chart or a 2-line VR800 program. Alternatively, the displayed optometry fonts can correspond to words or phrases.

[0121] During the display step, the size of the displayed optometric font can be adjusted based on the measured distance d. Alternatively, the size of the displayed optometric font can be determined based on a predefined distance d / 2 from the mirror.

[0122] Similarly, the angular size of the optometry font displayed on the screen 4 of the mobile device 2 can be adjusted based on the measured distance d.

[0123] By way of non-limiting example, consider the optometric font used in the following calculation as a Landolt ring with a notch, such that the virtual image of the displayed Landolt ring at a distance d has an angular size of Δθ. The physical size Δs of the notch displayed on the screen is given by the following equation:

[0124] (5) Δs=d×tan(Δθ)

[0125] For example, at a measured distance of 4.0m, for a visual acuity of 10 / 10, the notch Δθ of the displayed Landau ring should be equal to 1'. Using equation (5), the physical size Δs of the notch displayed on the screen is approximately equal to 1.16mm. For a mobile device 2 corresponding to a specific smartphone S, the physical size Δs of the notch displayed on the screen is equal to 1.16mm, corresponding to the number of pixels on the screen (Δs / p). s It is approximately equal to 25 pixels.

[0126] According to embodiments of this disclosure, the distance d between the front-facing camera and the mirror is frequently measured during the display step. For example, the distance d can be measured before displaying different optometry fonts or a series of optometry fonts. Preferably, the distance d between the front-facing camera and the mirror is measured in real time.

[0127] Advantageously, this allows for periodic (e.g., real-time) updates to the size and / or angle of the optometric font displayed on the screen of a mobile device, thereby providing a more accurate assessment of a person's visual acuity.

[0128] like Figure 1 As shown, the method for assessing a person's visual acuity further includes an assessment step S18. During the assessment step, the user's visual acuity is assessed.

[0129] The method for assessing a person's visual acuity may further include an input receiving step S16 prior to the assessment step. During the input receiving step, an instruction is received from the user in response to the displayed optometric font. The user's instruction may be received using voice recognition and / or gesture recognition and / or mobile device movement.

[0130] When the optometry text displayed on the screen 4 of the mobile device 2 is a word or phrase, the user can identify letters or read the sentence aloud. These instructions received from the user can be obtained using voice recognition (e.g., through the mobile device's microphone).

[0131] When the optometry font displayed on the screen 4 of the mobile device 2 is a Landau ring target with notches in different directions, the user can indicate the direction of the notch they perceive. The indication related to the direction of the notch perceived by the user can be obtained through voice recognition, using the microphone of the mobile device, by moving the mobile device, using the IMU of the mobile device or the front camera of the mobile device, and by moving the head and / or arm, using the front camera of the mobile device.

[0132] like Figure 4As shown, the mobile device 2 may further include physical volume up and volume down buttons 8a and 8b. Preferably, the volume up button 8a and volume down button 8b are located on one side of the mobile device 2, for example, on the left side of the mobile device 2 when facing the screen. During the input receiving step S16, the user can use the volume up button and volume down button 8a and 8b to provide instructions.

[0133] like Figure 5 As shown, the displayed optometry font can be a Landau ring target with notches in different directions. The displayed optometry font may further include a movable cursor 50. The movable cursor can be, for example, a circular art form that moves along different possible directions of the Landau ring target notches. In this case, the user can use the physical plus and minus buttons 8a and 8b of the mobile device to align the direction of the movable cursor 50 with the perceived Landau ring target notches. Then, after a short waiting period, for example, between 0.5 seconds and 2.0 seconds, preferably after a waiting period of 1.0 second, the selected position of the cursor can be confirmed.

[0134] During the evaluation process, a user's visual acuity can be assessed based on instructions received from the user.

[0135] According to embodiments of this disclosure, during the display step, a first series of various randomized optometric fonts corresponding to, for example, a first visual acuity level are presented to the user. During the evaluation step S18, the instruction received by the user is evaluated, and a score corresponding to the accuracy of the instruction can be attributed to the user. If the user achieves a sufficient score, the display step S14, the input receiving step S16, and the evaluation step S18 can be repeated using a second series of various randomized optometric fonts corresponding to a second visual acuity level.

[0136] This disclosure further relates to a computer-readable storage medium having a program recorded thereon, wherein the program causes a computer to perform the method according to this disclosure.

[0137] This disclosure also relates to a computer-readable, non-transitory program storage device that tangibly embodies a program having instructions executable by a computer to perform a method according to this disclosure. For example, the method includes the steps of: measuring a distance d between a front-facing camera of a mobile device and a mirror facing the front-facing camera of the mobile device; displaying optometry text on the screen of the mobile device; receiving input from a user of the mobile device; and assessing the user's visual acuity based on the received input.

[0138] like Figure 4As shown, this disclosure further relates to a mobile device 2, which includes at least one screen 4, at least one front-facing camera 6, a memory 10 (not shown), and a processor 12 (not shown). The screen and the front-facing camera are placed on the same side of the mobile device. The memory is configured to store instruction sequences. The processor is coupled to the memory 10, the at least one screen 4, and the at least one front-facing camera 6.

[0139] The processor 12 is configured to: execute a sequence of instructions to measure the distance d between the front-facing camera of the mobile device and a mirror facing the front-facing camera of the mobile device; display optometry text on the screen of the mobile device; receive input from the user of the mobile device; and evaluate the user's visual acuity based on the received input.

[0140] like Figure 6 As shown, this disclosure further relates to a display system for determining a person's visual acuity. For example, the display system is a system that includes a graphical user interface.

[0141] The display system includes a control unit. The control unit allows for the identification and processing of input data received from the user of the display system.

[0142] The display system further includes a display device. The display device allows the display of at least one optometric font and at least one movable cursor. The at least one optometric font is oriented in a direction selected from a predefined orientation list. The movable cursor is configured to be positioned and displayed in any direction from the predefined orientation list. The position of the displayed movable cursor is determined based on input received from the user and is identified and processed by a control device.

[0143] It will be apparent from the following discussion that, unless otherwise specifically stated, throughout this specification, discussions using terms such as “computing,” “calculating,” and “generating” refer to the actions and / or processes of a computer or computing system or similar electronic computing device that manipulate and / or transform data represented as physical (e.g., electronic) quantities within the registers and / or memory of the computing system into other data similarly represented as physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the computing system.

[0144] Embodiments of the present invention may include means for performing the operations described herein. Such means may be specifically constructed for the desired purpose, or the means may include a general-purpose computer or a digital signal processor (“DSP”) selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer-readable storage medium, such as, but not limited to, any type of disk, including floppy disks, optical disks, CD-ROMs, magneto-optical disks, read-only memory (ROM), random access memory (RAM), electronically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic cards or optical cards, or any other type of medium suitable for storing electronic instructions and capable of being coupled to a computer system bus.

[0145] The processes and displays presented herein are not inherently associated with any particular computer or other device. Various general-purpose systems can be used with the programs taught herein, or they may prove convenient for constructing more specialized devices to perform the desired methods. The desired architectures of various such systems will become apparent from the description below. Furthermore, embodiments of the invention are described without reference to any particular programming language. It should be understood that the teachings of the invention described herein can be implemented using various programming languages.

[0146] Many other modifications and variations will be apparent to those skilled in the art when referring to the foregoing illustrative embodiments. These embodiments are given by way of example only and are not intended to limit the scope of this disclosure, which is determined only by the appended claims.

[0147] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a (a) or (an)" does not exclude a plural. The mere fact that different features are described in mutually different dependent claims does not imply that combinations of these features cannot be used advantageously. No reference numerals in the claims should be construed as limiting the scope of this disclosure.

Claims

1. A method for assessing a user's visual acuity using a mobile device, said mobile device including at least a front-facing camera and a screen, the method comprising: - User positioning step, during which the user of the mobile device positions themselves in front of a mirror at a predefined distance. Place; - Mobile device positioning step, during which the mobile device is positioned such that the front camera of the mobile device faces the mirror; - Distance measurement step, during which the distance d between the front camera of the mobile device and the virtual image of the mobile device in the mirror is measured; - Display step, during which the screen of the mobile device displays the word "refraction"; - Evaluation step, during which the user's visual acuity is evaluated. - A mobile device data receiving step, during which mobile device data is received, the mobile device data including at least screen data related to the physical size of the mobile device's screen and at least camera data related to the angular resolution of the pixels of the front-facing camera, and wherein the distance d is measured at least based on the mobile device data. During the display step and the evaluation step, the distance between the front-facing camera and the mirror is measured periodically. ,and Among them, based on the measured distance The size and / or angle of the optometry font displayed during the display step are adjusted in real time.

2. The method according to claim 1, further comprising a distance control step prior to the display step, during which the measured distance d is compared with the predefined distance. Compare them.

3. The method of claim 2, further comprising a notification step, during which, based on the measured distance d and the predefined distance... The comparison is then sent to the user.

4. The method according to claim 1, wherein, The size and / or angle of the optometry font displayed during the display step are adjusted based on the measured distance d.

5. The method of claim 1, further comprising an input receiving step, during which an instruction is received from the user in response to the displayed optometry font, and in, The user's visual acuity is assessed based on instructions received from the user.

6. The method according to claim 5, wherein, The optometry font displayed on the screen of the mobile device during the display step includes a single Landau ring target with different orientations, and The instruction received from the user is related to the direction of the gap in the Landau ring sight as perceived by the user.

7. The method according to claim 6, wherein, The perceived direction of the Landau Ring beacon gap is indicated by the user using voice recognition and / or gesture recognition and / or the movement of the mobile device.

8. The method according to any one of claims 6 or 7, wherein, The displayed optometry text further includes a movable cursor, and the perceived direction of the Landau ring target on the screen of the mobile device is indicated by the position of the movable cursor.

9. The method according to claim 8, wherein, The mobile device includes physical volume up and volume down buttons, and The movable cursor is controlled by the user using the physical volume up and volume down buttons on the mobile device.

10. The method according to claim 1, wherein, The mobile device can be held with one hand.

11. A computer-readable, non-transitory program storage device tangibly embodies a program having instructions executable by the computer to perform methods including: - Measure the distance d / 2 between the front-facing camera of the mobile device and the mirror facing the front-facing camera of the mobile device; - Display the optometry text on the screen of the mobile device; - Receive input from the user of the mobile device, and - Evaluate the user's visual acuity based on the received input. - Receive mobile device data, the mobile device data including at least screen data related to the physical size of the mobile device's screen and at least camera data related to the angular resolution of the pixels of the front-facing camera, wherein, The distance d is measured based at least on the mobile device data. During the display of optometry text and the assessment of the user's visual acuity, the distance between the front-facing camera and the mirror is measured periodically. ,and Among them, based on the measured distance Adjust the size and / or angle of the optometry font displayed during the display of the optometry font in real time.

12. A mobile device, comprising: -Screen, - At least one front-facing camera - A memory configured to store instruction sequences. - A processor, the processor being coupled to the memory, the screen, and the at least one camera. The processor is configured to execute the instruction sequence to perform the following operations: - Measure the distance d / 2 between the front camera and the mirror facing the front camera; - Display the optometry text on the screen of the mobile device; - Receive input from the user of the mobile device, and - Evaluate the user's visual acuity based on the received input. - Receive mobile device data, the mobile device data including at least screen data related to the physical size of the mobile device's screen and at least camera data related to the angular resolution of the pixels of the front-facing camera, and wherein the distance d is measured at least based on the mobile device data. During the display of optometry text and the assessment of the user's visual acuity, the distance between the front-facing camera and the mirror is measured periodically. ,and Among them, based on the measured distance Adjust the size and / or angle of the optometry font displayed during the display of the optometry font in real time.

13. The mobile device of claim 12, further comprising a display system for determining a user's visual acuity, the display system comprising: - A control device for identifying and processing input data received from the user. - A display device for displaying at least one optometry font and at least one movable cursor, the optometry font being oriented in a direction selected from a predefined orientation list, and the movable cursor being configured to be displayed in any direction from the predefined orientation list, the orientation of the displayed movable cursor being based on input processed by the control device.

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