DEVICE FOR DETERMINING A SUITABLE GROUP OF VISUAL AIDS FOR A PERSON

Description

TECHNICAL FIELD TO WHICH THE INVENTION RELATES

[0001] The present invention relates to a device for determining a group of at least one vision aid device adapted to an individual's vision. TECHNOLOGICAL BACKGROUND

[0002] There are many different vision aids available, with extremely varied characteristics, both in terms of the type of vision aid provided, for example, improved visual acuity, contrast, or reduced glare, and in terms of the types of uses possible for this equipment, for example, indoor or outdoor use, use for reading, writing, looking into the distance...

[0003] Determining one or more visual devices best suited to an individual based on their vision and intended use of the device currently requires a relatively long and arduous process for both the optician and the individual.

[0004] We know from document EP1336924 A1 a device for selecting a lens adapted to an individual's vision.

[0005] Document EP1333393 A1 discloses that vision characteristics, ergonomic conditions of use and intended uses should be taken into account when selecting a vision aid. SUBJECT OF THE INVENTION

[0006] In order to remedy the aforementioned drawback of the prior art, the present invention proposes a device enabling the simple and efficient determination of at least one piece of equipment specifically adapted to the needs and wishes of an individual.

[0007] More specifically, the invention proposes a device for determining a group of at least one vision aid device adapted to the vision of an individual as described in claim 1.

[0008] Thus, the same device is adapted, on the one hand, to carry out vision tests on the individual allowing to determine precisely the technical characteristics of the equipment adapted to improve the individual's vision and, on the other hand, to record the individual's wishes regarding the use of the equipment.

[0009] Vision tests here are tests aimed at determining the optical, physical, mechanical, physiological or nervous functioning characteristics of an individual's eyes.

[0010] The use of the equipment here refers both to activities desired by the user, for example reading or seeing from a distance, and to conditions of use of the equipment, for example having hands free, using the equipment for long periods of time...

[0011] Finally, the device according to the invention is programmed to select a group of equipment adapted to the individual by cross-referencing the two types of information collected.

[0012] Other non-limiting and advantageous features of the device according to the invention are stated in claims 2 to 7. DETAILED DESCRIPTION OF A PROJECT EXAMPLE

[0013] The description that follows, with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out.

[0014] Regarding the attached drawings: there figure 1 is a schematic view of the device according to the invention, the figure 2 is a schematic view of one possible operating mode of the device of the figure 1 , there figure 3 is a schematic representation of a visual acuity test displayed on the device of the figure 1 , there figure 4 is a schematic representation of a contrast test displayed on the device of the figure 1 .

[0015] The device for determining a group of at least one visual equipment according to the invention can be used for any individual, regardless of the characteristics of their vision.

[0016] For example, it can help determine whether the most suitable equipment for an individual falls into the category of glasses with single-vision, bifocal, or progressive corrective lenses.

[0017] However, this device is particularly advantageous for determining a group of equipment intended to help a visually impaired person.

[0018] Indeed, the vision of visually impaired people can be affected by many factors. These can include, for example, a decrease in visual acuity, a reduction in contrast or color perception, a decrease in motor skills and / or a reduction in the field of vision of the person's eyes.

[0019] Furthermore, since the vision impairment of these individuals is particularly significant, it is not always possible to offer them vision aids suitable for use in all situations.

[0020] The device according to the invention then makes it possible to evaluate in a simple and quick way different aspects of the individual's vision as well as the uses envisaged by the individual of the vision aid equipment, in order to finally select a group of equipment making the best compromise between the technical characteristics necessary for the correction of the individual's vision defects and the ergonomic and practical characteristics necessary for the uses envisaged as a priority by this individual.

[0021] More specifically, there are several hundred vision aid devices for visually impaired people with different technical, ergonomic and practical characteristics.

[0022] All vision aid equipment can be segmented into seven groups of vision aid equipment: magnifying glasses, microscopes (or high-powered glasses), Galileo and Kepler's telescopic systems, portable electronic aids, electronic aids such as video magnifiers, lamps, filters.

[0023] On the figure 1 We have represented an example of a possible embodiment for the device according to the invention.

[0024] This device is presented here in the form of a touch tablet 10 comprising a touch display screen 11 and a frame 12 surrounding it.

[0025] This 10-inch tablet can be held by the individual whose vision is being assessed, placed on a table, or integrated into a more complex machine.

[0026] The tablet 10 includes computer capabilities as well as means to determine at least one characteristic of the vision of said individual in a step a) (block 100 of the figure 2), means to determine at least one use of the group of vision aids desired by the individual in step b) (block 150 of the figure 2 ), means for determining said group of vision aids based on the visual characteristic and the intended use by the individual in step c) (block 180 of the figure 2 ).

[0027] The computer systems are programmed to control the aforementioned systems.

[0028] The general operation of this device is schematically represented on the figure 2 .

[0029] In step a) represented by block 100 of the figure 2 The device according to the invention characterizes the wearer's vision. To this end, a series of tests represented by blocks 110 are carried out using device 10.

[0030] The results of these tests are processed by computer to determine the optical characteristics of the equipment adapted to the individual tested (block 120 of the figure 2 ).

[0031] Next, these optical characteristics are compared (block 140 of the figure 2 ) to the characteristics of the available equipment which are grouped in a database 130 to select a first set of suitable equipment (step c1)).

[0032] In step b) represented by blocks 150 and 250 on the figure 2Information regarding the individual's intended use of the equipment is collected by device 10. This information concerns, on the one hand, the ergonomic and practical conditions of use of the equipment (block 150) and, on the other hand, the activities desired by the individual (block 160). This information is processed by computer to deduce, on the one hand, the ergonomic and practical characteristics of the equipment adapted to the individual surveyed (block 160 of the figure 2 ) and on the other hand the equipment adapted to these activities (block 260).

[0033] Finally, in step c2), the results of the first selection and processing of the information collected on the conditions of use of the equipment are compared in an analysis step (block 170), in order to select the equipment suitable for the use intended by the individual from among those in the set presenting the optical characteristics likely to help the individual (block 180).

[0034] In step c3), the results of the second selection and processing of the information collected on the activities desired by the individual are compared in an analysis step (block 190), in order to select the equipment suitable for the activities envisaged by the individual from those of the second selection (block 200). Step a)

[0035] In step a), at least one of the following characteristics of the vision of the visually impaired person is determined: visual acuity, contrast sensitivity, extent of field of vision, glare, oculomotor function.

[0036] To this end, the tablet's computer systems are programmed to display on screen 11 a series of tests to evaluate the characteristics of the individual's vision.

[0037] Each test consists of displaying a symbol on the screen and receiving a signal emitted by the individual. The tablet's computer system is programmed to interpret this signal and deduce the test result.

[0038] The symbols displayed on the tablet correspond, for example, to a letter of an alphabet known to the individual or to a text written in a language spoken by the individual.

[0039] As explained in detail later, the sequence of tests is determined by the tablet's computer systems based on the results of previous tests.

[0040] Since the tablet 10 is touch-sensitive, the signal emitted by the individual corresponds, for example, to touching a particular area of ​​the tablet.

[0041] However, other embodiments can also be considered, in which the signal would be a sound signal emitted by the individual, for example when reading a letter or text on the tablet.

[0042] In the following sections, an example of a possible test will be described for different visual characteristics that can be assessed. Other tests can obviously be considered, and other visual characteristics can be tested. Visual acuity test

[0043] The visual acuity test, for example, is performed by displaying twelve lines of letters 20 as represented on the figure 3 Each line of letters consists of five capital letters. The letters used are the letters called Sloan letters, namely S, O, C, D, K, V, R, H, N, Z, as described in the book "Borish's Clinical Refraction", by William J. Benjamin, published in 2006 by Butterworth-Heinemann / Elsevier.

[0044] These letters are indeed easily recognizable. In a language other than French, and especially in a language using a different alphabet, one can also use all the letters of the alphabet or a different group of letters.

[0045] Using a button displayed on the screen, it is possible to distribute the letters randomly or in a predetermined pattern to perform visual acuity measurements under different conditions, for example, monocular or binocular vision, for a simple acuity check, or in the case of several successive tests on the same individual. This prevents the individual from memorizing the tests.

[0046] On each line, the size of the letters corresponds to a visual angle of discrimination, that is to say to a specific visual acuity.

[0047] The font size decreases from the first line to the last.

[0048] This means that if the individual can read the letters in a given line, their visual acuity is greater than or equal to the visual discrimination angle corresponding to the size of the letters in that line.

[0049] The letter size, for example, is calibrated for a reading distance of 40 cm. The visual acuity range tested here depends in part on the resolution characteristics of the touchscreen used. With current screens, it is possible to display lines of letters allowing for testing visual acuity ranging from 5 / 10 to 1 / 25. Preferably, the visual acuity increment between each line is constant, allowing for a consistent and precise measurement regardless of the visual acuity range being tested. In practice, the letters in each line are taller than those in the line below by a constant multiplicative factor equal to the cube root of 2. The progression of letter sizes is thus logarithmic.

[0050] For a given line, the spacing between two letters is equal to the size of the letter in that line.

[0051] The spacing between two successive lines is equal to the size of the line below, i.e., the smaller size. The contrast of the displayed letters is 100%.

[0052] The individual must then point to the last line they can read by touching the touchscreen at that line. The tablet then records the visual acuity corresponding to that line as the individual's visual acuity.

[0053] For example, if the individual can read the fifth line of letters which measure 0.582 centimeters, but no line of letters below this fifth line, the tablet's computer means deduce that the individual's visual acuity is 1 / 10.

[0054] Vision aids that can help the individual must then have a magnification of at least 6.

[0055] This action also brings up the following test. Functional acuity test

[0056] The functional acuity test makes it possible to determine the wearer's reading acuity and to obtain a more precise value of the useful magnification of the vision aid equipment adapted to the individual.

[0057] The characteristics of an individual's vision related to reading a text depend on the individual's identification abilities and oculomotor skills in addition to their visual acuity.

[0058] If these abilities are impaired, the magnification of the vision aid equipment adapted to the individual will need to be increased accordingly.

[0059] The functional acuity test also makes it possible to determine the useful magnification of the vision aid equipment in conditions closer to the individual's real-life conditions.

[0060] In the example of a functional acuity test described here, the tablet's computer systems are programmed to display on the screen a sentence consisting of 3 lines, thus presenting two line breaks.

[0061] Returning to the starting line can pose difficulties for individuals whose vision is particularly impaired (loss of landmarks, skipping lines, ...).

[0062] The words in the selected sentences are preferably chosen to be easy to understand. These sentences come, for example, from a well-known text such as a fairy tale or fable.

[0063] The words composing these sentences can also be chosen based on their frequency in the language in question. This frequency is determined by scientific studies. In French, the results of such a study can be found at the following web address: http: / / www.lexique.org.

[0064] This refers preferably to the most frequent words in the language in question.

[0065] Each sentence preferably comprises between 10 and 15 words with a homogeneous distribution of short words, containing 2 letters or less, medium-length words, containing between 3 and 5 letters, and long words, containing more than 5 letters.

[0066] A single sentence is displayed centered on screen 11. The letter size of the first sentence displayed after the visual acuity test is a letter size corresponding to an acuity lower than that determined for the individual during the visual acuity test, i.e. a larger letter size, to facilitate reading the first sentence.

[0067] The individual then displays other sentences with decreasing or increasing font sizes by touching the screen. The font size of the sentences follows a logarithmic progression similar to that of the font sizes of the different lines of letters displayed during the visual acuity test.

[0068] The individual or operator validates the sentence with the smallest font size for which the reading is smooth and error-free.

[0069] The size of the letters in the validated sentence corresponds to a visual acuity, which is reading acuity. If this functional acuity is lower than the wearer's visual acuity, the lower of the two values ​​is used by the tablet's computer system. Contrast test

[0070] The contrast test measures an individual's sensitivity to contrast. Contrast is defined as the ability to distinguish an object from its background. Contrast is expressed as a percentage or a logarithm. For example, it is calculated using the Michelson contrast ratio: LF - LO / LF + LO , where LF is the background luminance and LO is the object luminance.

[0071] When luminance is coded on one byte, the luminance of white is equal to 255 and the luminance of black is equal to 0.

[0072] A contrast of 100% corresponds to a black letter on a white background. The contrast test is performed in a fun, simple, and quick way.

[0073] For this purpose, letters chosen from the Sloan letters are displayed successively on a white background on the screen. The letters are much larger than the size corresponding to the individual's visual acuity, for example, a height of four centimeters.

[0074] For example, letters can be displayed with eight predefined contrasts equal to the following values: 100%, 50%, 25%, 10%, 5%, 2.5%, 1.25%, and 0.6%. The displayed contrasts can also be chosen with a constant step on a logarithmic scale.

[0075] The display screen is divided into 5 zones, shown schematically on the figure 4 .

[0076] Quadrants 15, 16, 17, and 18 correspond to the possible display areas for the letter, here an H displayed in the upper left quadrant. Area 19 is a response button indicating "no letters detected." The application displays a letter chosen randomly from Sloan's letters in one of quadrants 15, 16, 17, or 18, also chosen randomly.

[0077] The contrast of the displayed letter preferably decreases gradually.

[0078] When he sees a letter displayed, the individual must read the letter aloud and touch the quadrant in which he sees the letter appear.

[0079] When the individual does not see a letter displayed, they have the option to indicate this by touching area 19 of the screen.

[0080] The answer is validated if the individual correctly points to the displayed letter.

[0081] If the individual touches another area of ​​the screen, the computer systems consider that the individual did not perceive the displayed letter.

[0082] When a letter appears in a quadrant and the individual indicates that they see no letter or are in the wrong quadrant, this means that the maximum contrast perceived by the individual is between the contrast values ​​of the previous letter and the letter displayed.

[0083] We can consider including in the series of displayed letters, for example every two letters displayed, a letter with a random contrast.

[0084] This makes the test more fun and avoids putting the individual in a position of failure.

[0085] The tablet's computer system records the contrast value of the last letter viewed as the contrast threshold. The contrast threshold is definitively validated when the user has entered the same contrast threshold into the tablet's computer system three times.

[0086] Preferably, the first three letters displayed have contrasts of 100%, 50% and 25% and are easily identifiable by the individual.

[0087] This constitutes a training and confidence-building phase for the individual. It allows verification that the individual has correctly understood the operator's instructions. The results of this training phase are not taken into account in the calculation of contrast sensitivity. Scoring test

[0088] The pointing test helps to characterize the quality of an individual's eye-hand coordination. Visually impaired people often exhibit coordination difficulties that lead them to point to the side of a target. This characteristic related to an individual's vision plays an important role in the selection of assistive vision equipment.

[0089] For this test, the computer system is programmed to display black crosses on a white background, with 100% contrast, arranged randomly on the screen. The size of the cross is large enough to remain visible to the individual based on their initially measured visual acuity.

[0090] If visual acuity is less than or equal to 0.8 / 10, the size of the cross is five centimeters.

[0091] If visual acuity is between 0.8 / 10 and 2.5 / 10, the size of the cross is equal to 3 centimeters.

[0092] If visual acuity is greater than or equal to 2.5 / 10, the size of the cross is equal to 1.7 centimeters.

[0093] A pointing test involves displaying a series of ten successive crosses on the screen. It is also possible to display several series of crosses depending on whether one wants to assess coordination in monocular or binocular vision.

[0094] The individual is then asked to point to the center of the displayed cross as quickly as possible. For each displayed cross, the time taken by the individual to point is recorded, equal to the time between the display of the cross and the moment the individual touches the screen, and the pointing distance between the center of the cross, with coordinates X_cross, Y_cross, and the pointing zone of the finger, with coordinates X_finger, Y_finger.

[0095] After each scoring, a new cross is displayed on the screen in a random position.

[0096] For each test, we define the average of the difference between the position of the center of the cross and the position of the point touched by the individual.

[0097] The magnitude and direction of the deviation are calculated.

[0098] A training phase can be added to the test. This phase then displays 13 crosses. The results of the first 3 attempts are not counted. Glare test

[0099] The glare test determines an individual's sensitivity to light. Sensitivity is characterized by three parameters: the minimum light intensity measured in lux causing discomfort, the decrease in visual acuity and contrast sensitivity associated with this light intensity, the recovery time of visual acuity and contrast sensitivity after prolonged exposure to light.

[0100] The device consists of a display of letters with variable brightness and contrast, coupled with a light source. The light source includes a dimmer allowing for a luminous flux ranging from 0 to 7000 lux. The subject is positioned between 40 and 60 centimeters from the light source. The light source can be either central and point-like, or peripheral, for example, ring-shaped or circular.

[0101] Initially, a set of letters is displayed, for example two or three letters, whose size and contrast allow the individual to distinguish them clearly from the results of previous visual acuity and contrast tests.

[0102] The light output emitted by the light source is then gradually increased until the individual reports discomfort.

[0103] We then perform another visual acuity test and a contrast test to determine if there is a decrease in visual acuity and / or a loss of contrast.

[0104] If this is the case, the new visual acuity and contrast perception with this light flux are determined.

[0105] This step makes it possible to quantify glare by determining the maximum luminous flux and the consequences of this luminous flux on the individual's vision.

[0106] In a second step, the individual is illuminated with maximum light flux and the time required for the person to regain their initial visual acuity is measured.

[0107] This time, sometimes called "recovery time," is measured either with a stopwatch controlled by an operator or activated by a button on the tablet. Recovery time is measured between the moment the individual first touches the tablet's touchscreen, at the moment of illumination, and the moment the individual touches the screen again to indicate that their visual acuity has returned.

[0108] In practice, if this time is less than 30 seconds, it is not necessary to equip the individual with a filter. If this recovery time is between 30 seconds and one minute, it may be useful to offer the individual a filter, and if the time is greater than one minute, it seems necessary to offer a filter.

[0109] Further, more precise tests may be considered to confirm the need for a filter.

[0110] The result of the glare test helps to determine the usefulness of having a light filter integrated into the vision aid equipment to limit glare and, if necessary, to determine the characteristics of this filter. Field of vision extent test

[0111] The aim is to determine whether the field of vision is limited by the presence of a "blind" area called a scotoma, by a peripheral vision test with a static or dynamic target, of varying shape and luminance levels.

[0112] This test is performed by displaying a series of targets whose size and contrast are adjusted based on the results of previous tests so that the individual can observe them without difficulty. The visual field describes a map of the patient's perceptual areas according to their light sensitivity.

[0113] For example, an individual's field of vision can be determined by testing each eye with a tablet approximately 20 centimeters wide and 30 centimeters long, positioned at a reading distance of 40 centimeters from the individual, and with a vertical angle of + / -20 degrees. Alternatively, the maximum viewing angle of an individual can be measured for a tablet of given dimensions, as described, for example, in US document 7,549,743.

[0114] Analysis of the mapping and characteristics of the individual's visual field can be used to optimize the features of the equipment offered to that individual, such as the field of vision of the equipment, the need for contrast enhancement, the addition of filters and additional lighting. Oculomotor Test

[0115] This test determines whether the wearer's eyes move with the same agility in all directions.

[0116] For this, we can use a text reading test or a target tracking test.

[0117] The eye-tracking test also determines the stability of eye fixation. A target, for example, in the shape of a cross, with dimensions and contrast adapted to the wearer's visual acuity, is displayed in the center of the screen. A camera records and tracks the movements of the center of the eye, and more specifically the corneal reflection caused by the presence of a point light, such as a light-emitting diode (LED), directed at the eye using a well-established eye-tracking technique. The quality of eye fixation is assessed by asking the person to fixate on the center of the cross for 30 seconds. A camera records the variations in the position of the corneal reflection during the test. This allows for the determination of continuous or discontinuous eye movements.

[0118] The measurement can be performed using monocular or binocular vision.

[0119] The assessment of oculomotor quality impacts the choice of aid, and more specifically, the visual field associated with the equipment. A user with significant ocular fixation instability will experience greater comfort and performance with equipment offering a wide field of vision. For example, in such a case, a video magnifier would be preferable to a Galilean system because it offers a much wider field of vision. Color vision test

[0120] The purpose of the color vision test is to determine if an individual's vision has defects in color perception.

[0121] The test involves sorting several colored dots along three color axes. This sorting test is performed by displaying colored dots on a screen, which the individual can move by touching the screen to arrange them in order of their hue, starting from a given color. Only the hue of the displayed dots varies; the saturation and brightness of the dots remain the same. Red / Green and Yellow / Blue color blindness can thus be detected.

[0122] The tests described above are performed sequentially. As explained previously, the first test is the visual acuity test. The size of the signs subsequently displayed is determined based on the result of this test so that the individual can easily see them. The reading acuity test is then preferably performed, followed by the oculomotor test, the pointing test, the contrast sensitivity test, the visual field test, and the glare test, in that order. Step b)

[0123] In step b), the computer means determine at least one use of the group of at least one vision aid device desired by the individual.

[0124] The term "intended use" refers both to the activities that the individual wishes to perform with the equipment and to the desired ergonomic conditions of use of the equipment.

[0125] In practice, step b) determines whether at least one of the uses desired by the individual is actually desired: use for reading, use for writing, use for seeing from a distance, use for seeing up close, use for watching television, use for working on a screen located at an intermediate distance.

[0126] For a visually impaired person, distance vision refers to the visualization of an object located at a distance of 2 meters or more from the individual.

[0127] Near vision refers to the visualization of an object located at a distance from the individual of between 30 and 50 centimeters, for example equal to 40 centimeters.

[0128] An intermediate distance refers to an ergonomic working distance for the individual when using a screen. This distance is generally between 50 centimeters and one meter.

[0129] To achieve this, the system records, for each possible use considered by the computer system, an importance rating for that use for the individual. For example, the individual assigns an importance rating between 1 and 5 to each of the uses proposed above.

[0130] Preferably, in step b), at least one of the following ergonomic conditions desired by the individual for the intended uses is determined: outdoor use, indoor use, hands-free use, extended use.

[0131] Long-term use is defined as use exceeding a few minutes, for example, use exceeding 30 minutes.

[0132] The device records, globally for all intended uses, the desired ergonomic characteristics of the vision aid. To do this, the device records a binary ergonomic parameter, for example 1 or 0, + or -, indicating whether the considered ergonomic condition must be met by the vision aid to satisfy the individual.

[0133] Alternatively, it is possible to consider that the device records different ergonomic parameters for each use of the equipment.

[0134] The device records, for example, whether the individual wishes to keep their hands free or not. It also records whether the intended duration of use is long, for example to read a book for several hours, or short, for example to read product packaging in the supermarket. Step c)

[0135] The tablet's computer systems include in memory a pre-established list of vision aid equipment.

[0136] These vision aid devices are divided into seven categories of vision aid devices.

[0137] The first category includes magnifying glasses.

[0138] A magnifying glass is a very simple product that allows you to enlarge text or an object. Choosing a magnifying glass involves a compromise between magnification and field of view to ensure good reading speed.

[0139] There are different types of magnifying glasses, including, for example: Pocket magnifiers for short periods of use, indoors and outdoors; handheld magnifiers for daily use, short or long periods of use, indoors and outdoors; table magnifiers that cause less fatigue, for longer periods of use and to keep hands free; illuminated magnifiers that combine magnification and high contrast.

[0140] A second category includes microscopic glasses. These glasses consist of a frame and high-power ophthalmic lenses, for example, with a power between +6 and +36 diopters.

[0141] A third category includes the telescopic systems of Galileo and Kepler. These are devices designed to be mounted on a pair of glasses. They are intended for near or far vision. They allow visually impaired people to perform all types of work while keeping their hands free in most cases.

[0142] These devices can offer a wide range of magnification and provide a wide field of view.

[0143] Finally, for occasional use, for example reading a street name, handheld monocular devices will provide the necessary assistance while remaining discreet.

[0144] A fourth category includes portable electronic aids. These electronic aids offer very high magnification and improve contrast perception. They are easy to use.

[0145] Portable electronic aids are lightweight and compact. They allow for greater independence in daily life.

[0146] Portable electronic aids connect to all types of screens and can therefore be moved easily.

[0147] A fifth category includes electronic aids such as video magnifiers.

[0148] A sixth category includes lamps. Appropriate and good quality lighting significantly increases visual acuity.

[0149] The various available color temperatures allow for the selection of the most appropriate and comfortable lighting. This optimized lighting reduces the need for other necessary assistive devices.

[0150] Finally, the seventh category contains the filters.

[0151] They allow for improved contrast perception and reduced glare.

[0152] Like lamps, filters do not provide magnification and can be advantageously combined with other vision aid equipment.

[0153] Each vision aid device is listed in the form of an electronic register stored in the tablet's computer system.

[0154] Each entry in this registry includes an equipment identifier, first performance indices based on the assistance provided by this equipment for all possible vision characteristics of the individual, and second performance indices based on the adaptation of this equipment to all possible uses.

[0155] The identifier of the vision aid equipment corresponds, for example, to its name, a manufacturer's reference, or a code grouping several pieces of information, for example, the manufacturer's reference and the category of vision aid to which it belongs.

[0156] Preferably, each entry in the electronic register should also include an indicator of the ergonomic conditions of use of the corresponding equipment.

[0157] The first and second performance indices and the indicator of ergonomic conditions of use are determined empirically during an initial phase of the registry. They can be modified based on user experience with the device, particularly according to feedback provided by individuals using vision aids.

[0158] The initial performance indicators of the equipment depend primarily on the optical characteristics of the equipment, for example: magnification of the equipment, contrast enhancement capabilities, extent of the field of view with the equipment, possibility of use with a lamp or filter, short or medium focusing distance, fixed or variable, depth of field of the equipment.

[0159] In practice, the initial performance indicators for each device may, for example, include a first set of indicators encompassing all possible magnifications of the device. The registry entry for a vision aid device with a magnification between 5 and 10 would thus include the initial indicators 5, 6, 7, 8, 9, and 10 for magnification.

[0160] These initial ratings also include a binary index indicating whether the equipment is suitable for improving contrast perception: electronic vision aids, for example, are designed to achieve this improvement and will therefore have a rating of 1 for contrast enhancement. These electronic vision aids will also have a rating of 1 for magnification.

[0161] Optical equipment such as magnifying glasses is not suitable for improving contrast, therefore it will have a rating of 0 for contrast enhancement.

[0162] The second set of equipment performance indicators depends on the technical characteristics described above and other practical characteristics of the equipment, which make it more or less suitable for a given use, for example: possibility of carrying the equipment on oneself, or conversely possibility of fixing the equipment on a fixed support, possibility of fixing the equipment on a pair of glasses, distance of use of the equipment.

[0163] The second performance indices correspond, for example, to a score on five values, for example ranging from 0 to 4, of the equipment's performance for each use.

[0164] A magnifying glass with a built-in light is particularly well-suited for reading. Its reading performance rating will therefore be four.

[0165] However, this magnifying glass is not well-suited for writing. Its writing performance rating is therefore 0.

[0166] Since magnifying glasses are not suitable for distance and intermediate vision, the second performance indices of this magnifying glass for use in distance vision, for watching television and for working at an intermediate distance will be equal to 0.

[0167] The usability indicator here is a binary indicator showing the equipment's suitability for certain usage conditions.

[0168] For example, heavy, handheld equipment will not be suitable for extended use. Equipment with a very limited field of vision or a very shallow depth of field, making it difficult to maintain at the required working distance, will also not be suitable for extended use. Such equipment will, for instance, have a suitability indicator of 0 for extended use.

[0169] Conversely, a vision aid that can be used at an ergonomic distance and placed on a support allows for longer use and will have an indicator equal to 1 for this condition.

[0170] Equipment that requires a mains power connection is unsuitable for outdoor use. Small, lightweight, and compact equipment, such as certain magnifying glasses, which do not require a power supply, is perfectly suited for outdoor use.

[0171] For example, in the case of the magnifying glass described above, assuming that the illuminated tabletop magnifying glass is small and battery-operated, it will be suitable for short or long periods of use, since it can be placed on a surface and used outdoors.

[0172] According to the example of implementation described here, the computer means are programmed to pre-select, during a first sorting, from the pre-established list of vision aid equipment, i.e. from the different records of the register, a set of vision aid equipment adapted to help the individual according to at least one characteristic of his vision determined in step a).

[0173] For example, computer systems select from the registry only the equipment suitable for providing the necessary magnification corresponding to the functional acuity previously determined by the reading acuity test.

[0174] If the functional acuity test showed that the individual has a functional acuity of 1 / 10, the magnification of the adapted equipment is equal to 6.

[0175] The first sort then selects all the equipment whose first indices corresponding to the possible magnifications contain the value 6. These pieces of equipment form the set of equipment determined in step c1).

[0176] In a second sorting stage, computer systems are programmed to select, from this set of vision aid equipment, a subset of vision aid equipment that presents the ergonomic conditions of use desired by the individual.

[0177] During this second sorting, the computer systems select the equipment whose indicators regarding the conditions of use correspond to the ergonomic parameters of the use desired by the individual.

[0178] For example, if the individual indicated that they wished to use the equipment for a long period of time, indoors and with their hands free, the subset of equipment determined during the second sorting includes all the equipment from the set determined in the first sorting that can be used under these conditions.

[0179] During a third sorting, the computer means of the device select from the subset determined in the second sorting, the vision aid equipment of which at least one of the second performance indices is greater than or equal to the index of importance of the corresponding use assigned by the individual.

[0180] For example, if the individual assigned an index of 4 to reading use, 2 to writing use, and 0 to all other uses, the third sort selects the equipment whose second performance index for reading is equal to 4 and all those whose second performance index for writing is equal to 2, 3, or 4.

[0181] Finally, for each piece of equipment selected during the third sorting, the computer systems determine a performance score based on the second performance indices of each piece of equipment for each use and based on the importance index assigned to each use by the individual.

[0182] According to a first embodiment, the performance score is an overall score obtained by summing the second performance indices of each piece of equipment for all uses whose importance index for the individual is greater than a threshold value, for example greater than 2.

[0183] The device according to the invention then displays the equipment group thus determined in the form of a list classified according to this overall score, for example according to decreasing overall scores.

[0184] According to a second embodiment, the performance score determined is a weighted score reflecting more accurately the suitability of the equipment's performance for the possible uses of the equipment and the importance of these uses for the individual.

[0185] For each of the intended uses, the computer system calculates a ratio between the equipment's second performance index corresponding to that use and the index of that use's importance to the individual. The ratios for all uses are then summed to obtain the equipment's weighted score.

[0186] In practice, the device displays a list of the identified equipment, ranked according to decreasing weighted scores. The device can also transmit the list to a computer.

[0187] Alternatively, the device determines a single piece of equipment corresponding to the equipment with the highest overall or weighted score.

[0188] Numerous variations are possible. The sequence of sorting steps can be modified, for example. One could first consider the individual's intended uses before selecting equipment that meets their ergonomic requirements. At each sorting step, the selection is made from among the equipment selected in the previous step.

[0189] We can also consider any method known to a person skilled in the art for determining a performance score for each piece of equipment: any type of average, weighted average, etc.

[0190] Here, a group of at least one piece of equipment is defined as a group comprising one or more pieces of equipment belonging to one or more categories of equipment.

[0191] According to a simplified embodiment of the invention, the group of equipment determined by the device can correspond to one of the seven equipment categories described above. To this end, after one of the sorting operations described above, the device calculates a performance score associated with each equipment category containing items selected by the previous sorting. This category score is, for example, equal to the average of the overall scores or weighted scores described above for all items in that category. The device then displays the category with the highest score, or displays a ranking of the categories in descending order of scores.

[0192] Alternatively, the device according to the invention could obviously consist of a non-touchscreen tablet, a computer or telephone screen, or even include means for projecting onto a screen. Furthermore, the device could include means for adjusting the size of the displayed symbols according to the user's distance from the display screen.

[0193] Other types of vision tests can be considered, as well as psychosensory tests, for example to assess depth perception with stereoscopic tests, which may influence the choice of filter.

[0194] Tests to determine an individual's dominant eye, eye-head coordination, or ergonomics tests of equipment can also be carried out.

[0195] The results of these tests, as well as the results of pointing, glare, field of vision, color perception and oculomotor tests, are taken into account by computer means either during the steps described above, in order to refine the selection of equipment by taking this information into account, or at the end of the selection process, in order to adjust the performance score of the equipment and allow to optimize their ranking.

[0196] This information can also be taken into account to determine whether it is appropriate to add a second piece of equipment such as a filter or additional lighting to the equipment selected by the steps described above.

Claims

1. Device (10) for determining a group of at least one vision aid apparatus suitable for the vision of an individual, comprising computing means comprising in memory a pre-established list of vision aid apparatuses in the form of an electronic register, each record of which comprises: - an identifier of each vision aid apparatus, - first performance indices as a function of the aid provided by this apparatus for all possible vision characteristics of the individual and - second performance indices as a function of the suitability of this apparatus for all possible uses, - an indicator of at least one ergonomic condition of use of the corresponding apparatus, and programmed to: a) determine at least one characteristic of the vision of said individual, b) determine at least one use of the group of at least one vision aid apparatus desired by the individual and at least one ergonomic condition desired by the individual for the desired use, from among the following ergonomic conditions: use indoors, use outdoors, standard ergonomic use distance, long or short duration of use, c) determine said group of at least one vision aid apparatus as a function of the characteristic of the vision, of the ergonomic condition and of the use desired by the individual by carrying out the following steps: - in a step c1), preselecting, from among this pre-established list, a set of vision aid apparatuses suitable for aiding the individual as a function of at least the characteristic of their vision determined in step a), the computing means being programmed to preselect, from said register, all of the vision aid apparatuses for which at least one of said first indices corresponds to the associated vision characteristic of the individual, - in a step c2), selecting, from among said set of vision aid apparatuses that is determined in step c1), a subset of vision aid apparatuses exhibiting the ergonomic conditions of use desired by the individual, the computing means being programmed to select, from said set determined in step c1), the subset of vision aid apparatuses for which at least one indicator of the ergonomic conditions of use of the apparatus corresponds to the condition of use desired by the individual, - in a step c3), selecting, from among said subset of vision aid apparatuses that is determined in step c2), a subset of vision aid apparatuses that is most suitable for the uses desired by the individual, the computing means being programmed to select, from said set determined in step c2), the subset of vision aid apparatuses for which the second index is greater than a threshold value for at least one use desired by the individual.

2. Device (10) according to Claim 1, wherein, in step a), at least one of the following characteristics of the vision of the individual is determined: visual acuity, reading acuity, sensitivity to contrast, extent of the field of vision, glare, oculomotricity, eye-hand coordination, colour vision, stereoscopy.

3. Device (10) according to one of Claims 1 and 2, comprising a display part (11) and wherein, in step a), the characteristic of the vision of the individual is determined by virtue of a test of recognition of an image (20) displayed on said display part (11).

4. Device (10) according to Claim 3, wherein, in step a), several characteristics of the vision of the individual are determined successively and wherein the content and / or the sequencing of the subsequent vision tests is adapted as a function of the results of the previous tests.

5. Device (10) according to one of Claims 1 to 4, wherein, in step b), at least one of the following uses desired by the individual is determined: reading, writing, far vision, near vision, watching television, working on an object situated at an intermediate distance.

6. Device (10) according to one of Claims 1 to 5, wherein, in step b), the device records, for each desired use, an index of importance of this use for the individual.

7. Device according to one of the preceding claims, suitable for the determination of a group of at least one vision aid apparatus for a partially sighted individual.

8. Method for determining a group of at least one vision aid apparatus suitable for the vision of an individual, implementing computing means comprising in memory a pre-established list of vision aid apparatuses in the form of an electronic register, each record of which comprises: - an identifier of each vision aid apparatus, - first performance indices as a function of the aid provided by this apparatus for all possible vision characteristics of the individual and - second performance indices as a function of the suitability of this apparatus for all possible uses, - an indicator of at least one ergonomic condition of use of the corresponding apparatus, said method comprising the following steps carried out by said computing means: a) determining at least one characteristic of the vision of said individual, b) determining at least one use of the group of at least one vision aid apparatus desired by the individual and at least one ergonomic condition desired by the individual for the desired use, from among the following ergonomic conditions: use indoors, use outdoors, standard ergonomic use distance, long or short duration of use, c) determining said group of at least one vision aid apparatus as a function of the characteristic of the vision, of the ergonomic condition and of the use desired by the individual by carrying out the following steps: - in a step c1), preselecting, from among this pre-established list, a set of vision aid apparatuses suitable for aiding the individual as a function of at least the characteristic of their vision determined in step a), the computing means being programmed to preselect, from said register, all of the vision aid apparatuses for which at least one of said first indices corresponds to the associated vision characteristic of the individual, - in a step c2), selecting, from among said set of vision aid apparatuses that is determined in step c1), a subset of vision aid apparatuses exhibiting the ergonomic conditions of use desired by the individual, the computing means being programmed to select, from said set determined in step c1), the subset of vision aid apparatuses for which at least one indicator of the ergonomic conditions of use of the apparatus corresponds to the condition of use desired by the individual, - in a step c3), selecting, from among said subset of vision aid apparatuses that is determined in step c2), a subset of vision aid apparatuses that is most suitable for the uses desired by the individual, the computing means being programmed to select, from said set determined in step c2), the subset of vision aid apparatuses for which the second index is greater than a threshold value for at least one use desired by the individual.