Methods for assessing astigmatism in an individual - Patent application

Abstract

One aspect of the invention relates to a method (100) for assessing astigmatism in an individual, said method being performed following an assessment of the visual acuity of the individual's eye and a determination of the sphere of the individual's eye, said method (100) being performed based on the individual's prior optical correction, including a prescribed cylinder value and a prescribed axis value, of the individual's eye.

Description

[Technical Field]

[0001] The technical field of the invention is that of vision testing methods, and more particularly that of methods for assessing astigmatism.

[0002] The present invention relates to a method for assessing astigmatism in an individual, in particular a method for assessing astigmatism in an individual based on prior optical correction. The present invention also relates to a system, a computer program product, and a storage medium enabling the implementation of the method according to the invention. [Background technology]

[0003] A vision test is generally administered to an individual to determine whether correction is needed and, if so, what type of correction. Correction is then typically provided by eyeglasses or contact lenses obtained from an optician.

[0004] Due to the limited time that practitioners can devote to performing vision tests, it has been noted that 8-15% of the corrections prescribed in France ultimately do not fit the individual's vision. Of those individuals who are prescribed an inappropriate correction, 10% return to their practitioner and then to their optician to obtain new glasses or contact lenses, which results in considerable expense and time waste.

[0005] Among the values ​​prescribed for correction, astigmatism is often the cause of incorrect prescriptions. In fact, eye tests can reveal slight tensional astigmatisms that should not be prescribed, which can risk aggravating other factors such as myopia or visual discomfort. Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore necessary to quickly check the astigmatism value of the prescribed correction before the corresponding glasses or contact lenses are manufactured. [Means for solving the problem]

[0007] The present invention provides a solution to the aforementioned problems by allowing for a rapid assessment of an individual's astigmatism from a pre-prescribed correction.

[0008] A first aspect of the present invention is a method for assessing the astigmatism value of an eye of an individual, the method being carried out following assessing the visual acuity of the eye of the individual and determining a spherical power of the eye of the individual, the determined spherical power being non-zero, the method being performed from a prior optical correction of the individual including a prescribed cylinder value and a prescribed axis value of the eye of the individual, the method comprising: - positioning at least one eye chart at a fixed distance from the individual's eyes; - placing an initial lens having a value equal to the determined spherical power between the individual's eye and an eye chart; -If the prescribed cylinder value is zero, if the assessed visual acuity is equal to or greater than a first predetermined visual acuity threshold; - positioning a first cylinder having a minimum value along a first axis having a minimum value between the individual's eye and the initial lens; receiving information regarding an improvement in the individual's vision resulting from placing the first cylinder compared to without the first cylinder; and assigning an astigmatism value including a cylinder value of zero to the individual's eye if the received information does not reflect an improvement with the first cylinder; if the received information reflects an improvement due to the first cylinder, removing the first cylinder and determining the cylinder value using a rotating cross cylinder test, starting from the value of the first cylinder and the value of the first axis; - if the determined cylinder value is greater than the first cylinder value, determining an axis value by a rotating cross cylinder test starting from the determined cylinder value and the first axis value, and assigning to the individual's eye an astigmatism value comprising the determined cylinder value and the determined axis value; otherwise, assigning an astigmatism value to the eye of the individual, the astigmatism value including the determined cylinder value and the first axis value; If the assessed visual acuity is below a first predetermined visual acuity threshold, o placing a second cylinder between the individual's eye and the initial lens along a second axis, then along a third axis, then along a fourth axis, then along a fifth axis, the value of the second cylinder depending on the assessed visual acuity; receiving information regarding an improvement in the individual's vision resulting from positioning the second cylinder about one of the second axis, the third axis, the fourth axis, and the fifth axis; if the information reflects an improvement in visual acuity for one of the second, third, fourth and fifth axes, referred to as the preferred axis, removing the second cylinder and, starting from the value of the second cylinder and the value of the preferred axis, determining an axis value by a rotated cross cylinder test, starting from the value of the second cylinder and the determined axis value, determining a cylinder value by a rotated cross cylinder test, and assigning to the individual's eye an astigmatism value comprising the determined cylinder value and the determined axis value; otherwise, assigning an astigmatism value including a zero cylinder value to the individual's eye; o If the prescribed cylinder value is non-zero, o placing an initial cylinder between the individual's eye and an eye chart, the initial cylinder having a value equal to the prescribed cylinder value according to the prescribed axis value; o if the prescribed axis value is between the first axis value and the second axis value, or between the third axis value and the fourth axis value, or if the prescribed cylinder value is less than the first cylinder value and the prescribed axis value is between the fifth axis value and the sixth axis value, and the assessed visual acuity is equal to or greater than a second predetermined visual acuity threshold, determining the cylinder value by a rotational cross-cylinder test starting from the prescribed cylinder value and the prescribed axis value, and assigning an astigmatism value including the determined cylinder value and the prescribed axis value; o If the prescribed cylinder value is between the second and third cylinder values ​​and the prescribed axis value is between the seventh and eighth axis values, o placing a first lens between the individual's eye and the initial lens, the first lens having a value equal to the prescribed spherical equivalent of cylinder; o removing the first lens and placing, between the individual's eye and the initial lens, a third cylinder having a value equal to the prescribed cylinder value according to the prescribed axis value; receiving information regarding an improvement in the individual's vision resulting from placing the third cylinder relative to the first lens; assigning an astigmatism value including a cylinder value of zero to the eye of the individual if the information does not reflect an improvement in the individual's visual acuity with a third cylinder relative to the first lens; otherwise, removing the third cylinder, determining an axis value by a rotating cross cylinder test starting from the third cylinder value and the prescribed axis value, determining a cylinder value by a rotating cross cylinder test starting from the third cylinder value and the determined axis value, and assigning an astigmatism value to the individual's eye including the determined cylinder value and the determined axis value; otherwise, starting from the prescribed cylinder value and the prescribed axis value, determining an axis value by a rotated cross cylinder test, starting from the prescribed cylinder value and the determined axis value, determining a cylinder value by a rotated cross cylinder test, and assigning to the individual's eye an astigmatism value comprising the determined cylinder value and the determined axis value; The present invention relates to a method, comprising:

[0009] According to the present invention, an individual's astigmatism is estimated from a pre-prescribed astigmatism value as a function of a predetermined visual acuity, based on the assumption that the prescribed astigmatism value is close to the individual's true astigmatism value.

[0010] If the individual has not been prescribed astigmatism and their visual acuity is good, only the absence of horizontal astigmatism is guaranteed, since reverse or oblique astigmatism is synonymous with stress and therefore should not be prescribed as long as the visual acuity is good. To achieve this, a first cylinder with a minimum value along a first axis is placed in front of the individual's eye. If the individual prefers not to have the first cylinder, it is confirmed that the individual does not have astigmatism. Otherwise, a cylinder search around the value of the first cylinder is performed, and only if the resulting cylinder value is greater than the value of the first cylinder, an axis search around the value of the first axis is performed.

[0011] If the individual has not been prescribed astigmatism and the determined visual acuity is not good, the absence of weak astigmatism is ultimately confirmed by placing a second cylinder with values ​​related to the determined visual acuity along several axes. If the axis is not preferred, it is confirmed that the individual does not have astigmatism. If not, an axis search around the preferred axis value is performed, followed by a cylinder search around the value of the second cylinder.

[0012] If the prescribed axis value is close to horizontal or the prescribed cylinder value is strong, the prescribed axis value is close to the vertical axis, and the determined visual acuity is very good, the prescribed axis value is considered to be good and only a cylinder search around the prescribed cylinder value is performed.

[0013] If the prescribed cylinder value is low and the prescribed axis value is far from the horizontal axis, it is checked that the against-the-rule or oblique astigmatism is not due to fatigue or accommodation by placing a lens corresponding to the spherical equivalent of the prescribed cylinder value, followed by a third cylinder of a value equal to the prescribed cylinder value according to the prescribed axis value. If the individual likes the lens, the individual ultimately does not have astigmatism. Otherwise, an axis search around the prescribed axis value and then a cylinder search around the prescribed cylinder value are performed.

[0014] In other cases, an axis search around the prescribed axis value and then a cylinder search around the prescribed cylinder value is performed.

[0015] Using the determined visual acuity and prescribed astigmatism value allows for accurate assessment of an individual's astigmatism without the need to systematically perform a full axis search followed by a full cylinder search, thus reducing the time required.

[0016] In addition to the features just described in the previous paragraph, the method according to the first aspect of the invention can have one or more additional features from among the following, considered individually or according to any technically possible combination:

[0017] According to one alternative embodiment, the first and second visual acuity thresholds depend on a set of criteria that includes the age of the individual.

[0018] According to one alternative embodiment compatible with the previous alternative embodiment, the first visual acuity threshold is 10 / 10 and the second visual acuity threshold is 12 / 10.

[0019] According to one alternative embodiment that is compatible with the previous alternative embodiment, the first cylinder has a value of −0.25 diopters and the first axis has a value of 0°.

[0020] According to one alternative embodiment compatible with the previous alternative embodiment, the second axis has a value of 0°, the third axis has a value of 90°, the fourth axis has a value of 45°, and the fifth axis has a value of 135°.

[0021] According to one alternative embodiment that is compatible with the previous alternative embodiment, the first axis value is 0°, the second axis value is 10°, the third axis value is 170°, the fourth axis value is 180°, the first cylinder value is −0.5 diopters, the fifth axis value is 80°, and the sixth axis value is 100°.

[0022] According to one alternative embodiment that is compatible with the previous alternative embodiment, the second cylinder value is −0.5 diopters, the third cylinder value is 0 diopters, the seventh axis value is 30°, and the eighth axis value is 150°.

[0023] A second aspect of the invention relates to a method for assessing the astigmatism value of each of an individual's eyes, wherein for each eye of the individual a respective astigmatism value is assessed according to the method described above.

[0024] Thus, the above method may advantageously be performed on one eye and then the other eye of an individual to obtain astigmatism values ​​for both eyes of the individual.

[0025] A third aspect of the invention relates to a system for assessing astigmatism in an individual, which system allows the implementation of the method according to the invention, comprising: a screen configured to display at least one eye chart at a distance from the individual's eyes and to display at least one suggestion and / or selection symbol; a lens selector configured to position a lens or optical cylinder in front of an eye of the individual; an input interface configured to receive information regarding the improvement of the individual's vision after displaying the suggestions and / or selection symbols; a storage memory; a computer configured to perform one of the methods described above; This relates to a system including:

[0026] The method according to the invention can therefore be carried out by an individual or practitioner whose astigmatism is being assessed, who in fact selects himself, via the selection means, the suggestions and / or selection symbols displayed on the display means, and the calculator takes these selections into account in order to sequentially carry out the steps of the method.

[0027] Another aspect of the invention relates to a computer program product comprising instructions that, when the program is run on a computer, cause the computer to carry out the steps of the method according to the invention.

[0028] Another aspect of the invention relates to a computer-readable medium containing instructions which, when executed by a computer, cause the computer to perform the steps of the method according to the invention.

[0029] The invention and its different applications will be better understood on reading the following description and on examining the accompanying drawings.

[0030] The drawings are included to illustrate the purpose of the invention and are not limiting in any way. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a block diagram illustrating the steps of a method according to the present invention; [Figure 2] 1 is a schematic diagram of a system according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0032] Unless otherwise specified, identical elements appearing in different figures will have a single reference number.

[0033] A first aspect of the present invention relates to a method for assessing the astigmatism of an individual, i.e. for determining the astigmatism value of each eye of an individual.

[0034] The astigmatism value includes a cylinder value and, if the cylinder value is non-zero, an axis value.

[0035] The method according to the invention is carried out from a pre-prescribed correction for the individual, including a prescribed astigmatism value for each eye of the individual, i.e. a prescribed cylinder value and a prescribed axis value for each eye of the individual.

[0036] The method according to the invention is carried out following, on the one hand, an assessment of the visual acuity of each eye of the individual, i.e., following determination of the visual acuity of each eye of the individual, and, on the other hand, following determination of the spherical power of each eye of the individual.

[0037] For each eye of the individual, the spherical power is determined, for example, from a correction previously prescribed for the individual, and further includes the spherical power prescribed for the eye of the individual. The spherical power determined for each eye is non-zero.

[0038] FIG. 1 is a block diagram illustrating the sequence of steps of a method 100 according to the present invention.

[0039] The method 100 according to the present invention is performed within the monocular steps of a vision test, i.e. the steps of the method 100 according to the present invention are performed for one eye of an individual and then for the other eye of the individual.

[0040] The method 100 according to the present invention is performed, for example, for the right eye and then for the left eye of an individual.

[0041] The first step 101 of the method 100 according to the invention consists of placing at least one eye chart at a certain distance from the individual's eyes.

[0042] "Eye chart" means any letter or shape used to measure visual acuity.

[0043] The first step 101 consists in placing in front of the individual's eyes at least one group of letters corresponding to the individual's minimum expected visual acuity, which may for example depend on the individual's age or correspond to, for example, 10 / 10 visual acuity.

[0044] The eye chart is, for example, positioned at least 4 meters from the individual's eyes, preferably at least 5 meters from the individual's eyes.

[0045] A second step 102a of the method 100 according to the invention consists of placing an initial lens in front of the individual's eye, the initial lens having a value equal to the spherical power determined before the implementation of the method 100 according to the invention. The initial lens is then placed between the individual's eye and an eye chart.

[0046] If the first condition C1 is met, i.e. the cylinder value prescribed for the individual's eye is zero, it is checked whether the second condition C2 is met.

[0047] If the second condition C2 is met, i.e. if the pre-assessed visual acuity of the individual's eye is greater than or equal to the first predetermined visual acuity threshold, the third step 103 of the method 100 according to the invention is executed.

[0048] The first visual acuity threshold is, for example, defined as a function of a set of parameters including, for example, the age of the individual.

[0049] The first visual acuity threshold is, for example, 10 / 10.

[0050] The third step 103 of the method 100 according to the present invention comprises placing a first cylinder having a minimum value in front of the individual's eye along a first axis having a minimum value, and the first cylinder is then positioned between the individual's eye and the initial lens.

[0051] The first cylinder has a value of, for example, -0.25 diopters, and the first axis has a value of, for example, 0°.

[0052] If the third condition C3 is met, i.e. if the individual prefers not having the first cylinder to having the first cylinder, or if the individual does not see a difference between having or not having the first cylinder, the fourth step 104 of the method 100 according to the present invention is executed.

[0053] "An individual prefers not having the first cylinder to having the first cylinder" means that the individual feels less discomfort to their vision without the first cylinder than with the first cylinder, i.e., that their vision appears more comfortable to them without the first cylinder. In particular, the individual's preference can be reflected by receiving information emitted by the individual regarding the improvement in vision resulting from placing the first cylinder compared to without the first cylinder. When condition C3 is met, the received information does not reflect an improvement due to the first cylinder. For example, the information may be received via a selection device (touch screen or selection joystick) through which the individual inputs their preference.

[0054] The fourth step 104 of the method 100 according to the invention consists in assigning to the individual's eye an astigmatism value that includes a zero cylinder value.

[0055] If the third condition C3 is not met, i.e., if the individual prefers having the first cylinder to not having the first cylinder (in other words, the information received reflects an improvement due to the first cylinder), the fifth step 105 of the method 100 according to the present invention is executed.

[0056] The fifth step 105 of the method 100 according to the invention consists of removing the first cylinder from in front of the individual and then performing a rotating cross cylinder test, starting from the value of the first cylinder and the value of the first axis, to determine the cylinder value.

[0057] If the fourth condition C4 is met, i.e. the cylinder value determined in the fifth step 105 is greater than the value of the first cylinder, a sixth step 106 of the method 100 according to the invention is executed.

[0058] A sixth step 106 of the method 100 according to the invention consists of carrying out a rotational cross cylinder test, starting from the cylinder value and the first axis value determined in the fifth step 105, to determine an axis value, and then assigning to the individual's eye an astigmatism value comprising the cylinder value determined in the fifth step 105 and the axis value determined in the sixth step 106.

[0059] If the fourth condition C4 is not fulfilled, i.e. the cylinder value determined in the fifth step 105 for the fifth cylinder is smaller than the value for the first cylinder, then the seventh step 107 of the method 100 according to the invention is executed.

[0060] The seventh step 107 of the method 100 according to the invention consists in assigning to the individual's eye an astigmatism value comprising the cylinder value and the value of the first axis determined in the fifth step 105 .

[0061] If the second condition C2 is not met, i.e. if the pre-assessed visual acuity of the individual's eye is below the first predetermined visual acuity threshold, the eighth step 108 of the method 100 according to the invention is executed.

[0062] The eighth step 108 of the method 100 according to the present invention comprises placing a second cylinder in front of the individual's eye, the second cylinder having a value corresponding to the previously assessed visual acuity of the individual's eye, between the individual's eye and the initial lens.

[0063] The value of the second cylinder is determined from the visual acuity previously assessed for the individual eye, for example according to table 5-1 of the Methode du Brouillard, section 5-9 of the September 2012 Opto-Com edition of the book "Cours d'Optometrie" by Jean-Charles Allary.

[0064] The second cylinder is first positioned along the second axis, then along the third axis, then along the fourth axis, and then along the fifth axis.

[0065] The second axis and the fourth axis, the third axis and the fifth axis, and the third axis and the fourth axis are, for example, spaced apart by about 45°.

[0066] The second axis may have a value of, for example, 0°, the third axis may have a value of, for example, 90°, the fourth axis may have a value of, for example, 45°, and the fifth axis may have a value of, for example, 135°.

[0067] If the fifth condition C5 is met, i.e., if the individual prefers one of the second, third, fourth and fifth axes, the ninth step 109 of the method 100 according to the present invention is executed. The individual's preference can be expressed by receiving information about the improvement in the individual's visual acuity resulting from positioning the second cylinder about one of the second, third, fourth and fifth axes. Thus, condition C5 is met when said information reflects an improvement in visual acuity about one of the axes, referred to as the preferred axis.

[0068] By "the individual prefers one of the axes" it is meant that the individual experiences less discomfort to their vision when the second cylinder is positioned along the preferred axis.

[0069] The ninth step 109 of the method 100 according to the present invention consists of removing the second cylinder from in front of the individual's eye, then performing a rotated cross cylinder test starting from the value of the second cylinder and the value of the preferred axis to determine an axis value, then performing a rotated cross cylinder test using the second cylinder value and the axis value determined in said ninth step 109 to determine a cylinder value, and then assigning an astigmatism value to the individual's eye comprising the cylinder value determined in said ninth step 109 and the axis value determined in said ninth step 109.

[0070] If the fifth condition C5 is not met, i.e. if the individual does not identify a preferred axis among the second, third, fourth and fifth axes, the tenth step 110 of the method 100 according to the present invention is executed.

[0071] The tenth step 110 of the method 100 according to the invention consists of assigning to the individual's eye an astigmatism value that includes a zero cylinder value.

[0072] If the first condition C1 is not satisfied, i.e., if the cylinder value prescribed for the individual's eye is non-zero, the method 100 includes step 102b of placing an initial cylinder (also called a "cylinder lens") between the individual's eye and the vision chart, the initial cylinder having a value equal to the prescribed cylinder value according to the prescribed axis value. The initial cylinder is then placed between the individual's eye and the vision chart.

[0073] It is then checked whether the sixth condition C6 is met.

[0074] If the sixth condition C6 is met, i.e., if the prescribed axis value of the individual's eye is between the first axis value and the second axis value, or between the third axis value and the fourth axis value, or if the prescribed cylinder value of the individual's eye is less than the first cylinder value and the prescribed axis value of the individual's eye is between the fifth axis value and the sixth axis value, and the pre-assessed visual acuity of the individual's eye is equal to or greater than the second predetermined visual acuity threshold, then the eleventh step 111 of the method 100 according to the present invention is executed.

[0075] The first axis value, the second axis value, the third axis value, and the fourth axis value are, for example, axis values ​​close to the horizontal axis.

[0076] The first axis value is, for example, 0°, the second axis value is, for example, 10°, the third axis value is, for example, 170°, and the fourth axis value is, for example, 180°.

[0077] The first cylinder value is, for example, a strong cylinder value, and the fifth and sixth axis values ​​are, for example, values ​​close to the vertical axis.

[0078] The first cylinder value is, for example, -0.5 diopters, the fifth axis value is, for example, 80°, and the sixth axis value is, for example, 100°.

[0079] The second visual acuity threshold is, for example, defined as a function of a set of parameters including, for example, the age of the individual.

[0080] The second visual acuity threshold is, for example, 12 / 10.

[0081] An eleventh step 111 of the method 100 according to the present invention consists of carrying out a rotational cross cylinder test, starting from the cylinder value prescribed for the individual's eye and the axis value prescribed for the individual's eye, in order to determine a cylinder value, and then assigning to the individual's eye an astigmatism value comprising the cylinder value and the axis value prescribed for the individual's eye determined during this eleventh step 111.

[0082] If the sixth condition C6 is not met, i.e. if the axis value prescribed for the individual's eye is not between the first axis value and the second axis value, or is not between the third axis value and the fourth axis value, or if the cylinder value prescribed for the individual's eye is equal to or greater than the first cylinder value, or if the axis value prescribed for the individual's eye is not between the fifth axis value and the sixth axis value, or if the visual acuity assessed for the individual's eye is less than the second predetermined visual acuity threshold, then it is checked whether the seventh condition C7 is met.

[0083] If the seventh condition C7 is met, i.e., if the cylinder value prescribed for the individual's eye is between the second cylinder value and the third cylinder value and the axis value prescribed for the individual's eye is between the seventh axis value and the eighth axis value, the twelfth step 112 of the method 100 according to the present invention is executed.

[0084] The second and third cylinder values ​​may be, for example, low or zero cylinder values.

[0085] The seventh and eighth axis values ​​are, for example, diagonal axis values ​​away from the horizontal axis.

[0086] The second cylinder value is, for example, -0.5 diopters, the third cylinder value is, for example, 0 diopters, the seventh axis value is, for example, 30°, and the eighth axis value is, for example, 150°.

[0087] A twelfth step 112 of the method 100 according to the present invention comprises placing a first lens in front of the individual's eye, the first lens having a value equal to the spherical equivalent of the cylinder prescribed for the individual's eye, between the individual's eye and the initial lens.

[0088] A thirteenth step 113 of the method 100 according to the present invention comprises removing the first lens from in front of the individual's eye, and then placing a third cylinder having a value equal to the cylinder value prescribed for the individual's eye according to the axis value prescribed for the individual's eye. The third cylinder is then placed between the individual's eye and the initial lens.

[0089] If the eighth condition C8 is met, i.e., if the individual prefers the first lens over the third cylinder, the fourteenth step 114 of the method 100 according to the present invention is executed. The individual's preference can be reflected by receiving information about the improvement in the individual's vision resulting from positioning the third cylinder relative to the first lens. Thus, condition C8 is met if the information does not reflect an improvement in the individual's vision with the third cylinder compared to the first lens.

[0090] By "an individual prefers the first lens to the third cylinder" it is meant that the individual experiences less discomfort to their vision with the first lens than with the third cylinder.

[0091] A fourteenth step 114 of the method 100 according to the invention consists of assigning to the individual's eye an astigmatism value that includes a zero cylinder value.

[0092] If the eighth condition C8 is not met, ie if the individual prefers the third cylinder to the first lens, the fifteenth step 115 of the method 100 according to the invention is carried out.

[0093] The fifteenth step 115 of the method 100 according to the present invention consists of removing the third cylinder from in front of the individual's eye, then performing a rotated cross cylinder test starting from the value of the third cylinder and the axis value prescribed for the individual's eye to determine an axis value, then performing a rotated cross cylinder test using the third cylinder value and the axis value determined in the fifteenth step 115 to determine a cylinder value, and then assigning an astigmatism value to the individual's eye including the cylinder value determined in the fifteenth step 115 and the axis value determined in the fifteenth step 115.

[0094] If the seventh condition C7 is not met, i.e. if the cylinder value prescribed for the individual's eye is not between the first and second cylinder values, or if the axis value prescribed for the individual's eye is not between the fifth and sixth axis values, the sixteenth step 116 of the method 100 according to the present invention is executed.

[0095] The sixteenth step 116 of the method 100 according to the present invention consists of carrying out a rotated cross cylinder test, starting from the cylinder value prescribed for the individual's eye and the axis value prescribed for the individual's eye, to determine an axis value, then carrying out a rotated cross cylinder test, starting from the cylinder value prescribed for the individual's eye and the axis value determined during this sixteenth step 116, to determine a cylinder value, and then assigning to the individual's eye an astigmatism value comprising the cylinder value determined in the sixteenth step 116 and the axis value determined in the sixteenth step 116.

[0096] A second aspect of the present invention relates to a method for assessing the astigmatism value of each of an individual's eyes, where for each eye of the individual, the respective astigmatism value is assessed in accordance with method 100 according to the first aspect of the present invention. Thus, method 100 according to the first aspect of the present invention can be performed on one eye of a subject and then on the other eye to obtain astigmatism values ​​for both eyes of the subject.

[0097] A third aspect of the present invention relates to a system for assessing astigmatism in an individual, which allows the implementation of the method 100 according to the present invention by the individual or a third party, for example a medical practitioner.

[0098] FIG. 2 shows a schematic diagram of a system 200 according to the present invention.

[0099] The system 200 includes a display means configured to display at least one eye chart at a distance from the individual's eyes.

[0100] The display means is, for example, a screen 201 or a poster as shown in FIG.

[0101] According to one embodiment, the display means 201 is also adapted to display suggestion and / or confirmation symbols.

[0102] For example, the display means may be configured to display suggestions for identifying preferred lenses, axes, or cylinders.

[0103] And, the system 200 also includes an input interface 206 configured to select suggestions and / or symbols.

[0104] The input interface 206 is, for example, a remote controller, a tablet, a console, or a microphone as illustrated in FIG.

[0105] The system 200 also includes a lens selector 202 configured to position an optical lens or cylinder in front of the individual's eye.

[0106] Lens selector 202 is, for example, an autorefractor head as illustrated in FIG.

[0107] The system 200 according to the invention comprises a storage memory 203 and a calculator 204 configured to manage a display means, a lens selector 202 and an input interface 206 to enable the implementation of the steps of the method 100 according to the invention.

[0108] For example, following the third step 103 of method 100, the display means displays a first suggestion that allows for selection using the first cylinder, a second suggestion that allows for selection without using the first cylinder, and a third suggestion that indicates that there is no difference between using the first cylinder or not. The individual selects the third suggestion via input interface 206, and calculator 204 processes the selection of the third suggestion to begin performing the fourth step 104 of method 100.

Claims

1. A method (100) for evaluating the astigmatism value of an individual eye, characterized in that it is performed following the evaluation of the visual acuity of the individual eye and the determination of the spherical power of the individual eye, wherein the determined spherical power is non-zero, and the method (100) is performed from the individual's prior optical correction, including the prescribed cylinder value and prescribed axis value of the individual eye, and the method is - Placing at least one eye chart at a certain distance from the individual's eyes (101), - Placing an initial lens having a value equal to the determined spherical power between the individual's eye and the visual acuity chart (102a), - If the prescribed cylinder value is zero (C1), o If the evaluated visual acuity is equal to or greater than the first predetermined visual acuity threshold (C2), - Placing a first cylinder having a minimum value along a first axis having a minimum value between the individual's eye and the initial lens (103), - Receiving information regarding the improvement in an individual's visual acuity resulting from the placement of the first cylinder compared to the absence of the first cylinder, >If the received information does not reflect the improvement by the first cylinder (C3), assign an astigmatism value including a zero cylinder value to the individual's eye (104), >If the received information reflects the improvement made by the first cylinder (C3), the first cylinder is removed, and the cylinder values ​​are determined by a rotational cross-cylinder test, starting from the values ​​of the first cylinder and the first shaft (105). - If the determined cylinder value is greater than the value of the first cylinder (C4), the axis value is determined by a rotating cross cylinder test, starting from the determined cylinder value and the value of the first axis, and an astigmatism value including the determined cylinder value and the determined axis value is assigned to the individual's eye (106), - Otherwise, assign an astigmatism value to the individual's eye, including the determined cylinder value and the determined first axis value (107), o If the evaluated visual acuity is below the first predetermined visual acuity threshold, - Positioning a second cylinder between the individual's eye and the initial lens along a second axis, then a third axis, then a fourth axis, then a fifth axis (108), wherein the value of the second cylinder depends on the evaluated visual acuity (108), - Receiving information regarding the improvement in an individual's visual acuity resulting from positioning the second cylinder on one of the axes, including the second, third, fourth, and fifth axes. >If the information reflects an improvement in visual acuity in one of the axes referred to as the preferred axis among the second, third, fourth, and fifth axes (C5), the second cylinder is removed, the axis values ​​are determined by a rotating cross-cylinder test starting from the second cylinder value and the preferred axis value, the cylinder values ​​are determined by a rotating cross-cylinder test starting from the second cylinder value and the determined axis value, and an astigmatism value including the determined cylinder value and the determined axis value is assigned to the individual's eye (109), >Otherwise, assign astigmatism values ​​including zero cylinder values ​​to an individual's eye (110), - If the prescribed cylinder value is not zero, (102b) Placing an initial cylinder between the individual's eye and the visual acuity chart, having a value equal to the prescribed cylinder value according to the prescribed axis value, o If the prescribed axis value is between the first axis value and the second axis value, or between the third axis value and the fourth axis value, or if the prescribed cylinder value is less than the first cylinder value, and the prescribed axis value is between the fifth axis value and the sixth axis value, and the evaluated visual acuity is equal to or greater than the second predetermined visual acuity threshold (C6), the cylinder value is determined by a rotating cross cylinder test starting from the prescribed cylinder value and prescribed axis value, and an astigmatism value including the determined cylinder value and prescribed axis value is assigned (111), oWhen the prescribed cylinder value is between the second cylinder value and the third cylinder value, and the prescribed axis value is between the seventh axis value and the eighth axis value (C7), - A first lens having a value equal to the equivalent spherical power of the prescribed cylinder value is placed between the individual's eye and the initial lens (112), - Removing the first lens and placing a third cylinder between the individual's eye and the initial lens, having a value equal to the prescribed cylinder value according to the prescribed axis value (113), - Receiving information regarding the improvement in an individual's visual acuity resulting from positioning a third cylinder relative to the first lens, >If the information does not reflect the improvement in the visual acuity of an individual having a third cylinder relative to the first lens (C8), assign an astigmatism value to the individual's eye that includes a cylinder value of zero (114), Otherwise, remove the third cylinder, determine the axis value by rotating cross cylinder test starting from the third cylinder value and the prescribed axis value, determine the cylinder value by rotating cross cylinder test starting from the third cylinder value and the determined axis value, and assign an astigmatism value including the determined cylinder value and the determined axis value to the individual's eye (115), o Otherwise, starting from the prescribed cylinder value and prescribed axis value, the axis value is determined by a rotating cross cylinder test, and starting from the prescribed cylinder value and determined axis value, the cylinder value is determined by a rotating cross cylinder test, and an astigmatism value including the determined cylinder value and determined axis value is assigned to the individual's eye (116), Methods that include...

2. The method according to claim 1 (100), wherein the first visual acuity threshold and the second visual acuity threshold depend on a set of criteria including the individual's age.

3. The method according to claim 1 (100), wherein the first visual acuity threshold is 10 / 10 and the second visual acuity threshold is 12 / 10.

4. The method according to claim 1 (100), wherein the first cylinder has a value of -0.25 diopters and the first axis has a value of 0°.

5. The method according to claim 1 (100), wherein the second axis has a value of 0°, the third axis has a value of 90°, the fourth axis has a value of 45°, and the fifth axis has a value of 135°.

6. The method according to claim 1 (100), wherein the first axis value is 0°, the second axis value is 10°, the third axis value is 170°, the fourth axis value is 180°, the first cylinder value is -0.5 diopters, the fifth axis value is 80°, and the sixth axis value is 100°.

7. The method according to claim 1 (100), wherein the second cylinder value is -0.5 diopters, the third cylinder value is 0 diopters, the seventh axis value is 30°, and the eighth axis value is 150°.

8. A method for evaluating the astigmatism values ​​of each of an individual's eyes, wherein the astigmatism value of each of the individual's eyes is evaluated according to claim 1.

9. A system (200) for evaluating an individual's astigmatism, which enables the automated implementation of the method (100) according to any one of claims 1 to 8, - A screen (201) configured to display at least one eye chart at a certain distance from the individual's eyes, and to display at least one suggestion and / or selection symbol, - A lens selector (202) configured to position a lens or optical cylinder in front of an individual's eyes, - An input interface (206) configured to receive information on the improvement of an individual's vision after displaying a suggestion and / or selection symbol, - Memory (203), - A computer (204) configured to carry out the method (100) described in any one of claims 1 to 8, A system that includes this.

10. A computer program product that, when executed on a computer, includes instructions causing the computer to perform the steps (100) of the method according to any one of claims 1 to 8.

11. A computer-readable recording medium that, when executed by a computer, includes instructions causing the computer to perform a step (100) according to any one of claims 1 to 8.

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