Detection and correction of a person's current refractive error and current fluctuations in accommodation

Abstract

To provide a method for detecting variation of a present refractive error of a person.SOLUTION: The current invention relates to a method for detecting variation of a present refractive error of a person. The method includes a step (S1) for acquiring an optical instrument including an optical lens whose refractive function corrects initial refractive error of a person. The optical instrument further includes a processing circuit including a processor operably connected to a memory. The method includes a step (S6) for acquiring present value of a parameter by using the memory, and the present value shows variation of an initial refractive error of the current refractive error of the person. The method includes a step (S7) which uses the processing circuit to detect variation of the initial refractive error of the present refractive error of the person on the basis of the acquired present value of the parameter.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates generally to optical products, and more particularly to a method, a computer program, a computer storage medium, a processing circuit, and an optical device for detecting a change in a person's current refractive error or a change in the current accommodation, and a method, a computer program, a computer storage medium, a processing circuit, and an optical device for correcting a person's refractive error or accommodation deficiency. [Background technology]

[0002] Between appointments with an eye care practitioner (ECP), a person's refractive error can naturally change.

[0003] Common refractive errors include myopia, hyperopia, and astigmatism.

[0004] Myopia corresponds to the eye focusing light in front of the retina instead of on it, resulting in distant objects appearing blurry.

[0005] Hyperopia corresponds to the eye focusing light at its optic nerve rather than on the retina, resulting in close objects appearing blurred.

[0006] Astigmatism refers to an eye that does not focus light evenly on the retina, resulting in both near and distant objects appearing blurry.

[0007] In particular, it has been demonstrated that when a person's myopia is undercorrected, i.e. when the current prescription for compensating for said myopia with an optical device is more advanced than the corresponding original prescription for the optical device that the person normally wears, the myopia progresses more quickly than if it were perfectly corrected.

[0008] Myopia is a common refractive error, currently affecting approximately one-third of the population. High myopia poses a higher risk of retinal and choroidal disease. Several methods and products are used to slow the progression of myopia. Of these solutions, corneal orthodontic contact lenses, soft confocal contact lenses, topical medications such as atropine and pirenzepine, and progressive or confocal ophthalmic lenses have been shown to be more or less effective through randomized controlled trials.

[0009] Slowing the progression of myopia as soon as possible after its onset is important and could potentially benefit millions of children and adults worldwide.

[0010] A strategy to detect myopia progression as soon as possible after its onset is to schedule regular ECP appointments. However, this strategy is not very practical. Even during controlled trials, visits for refractive error evaluation are at most every 6 to 12 months. It is not uncommon for myopic children to be exposed to blurred vision due to myopia progression several months after each ECP examination and the fabrication of new glasses. The glasses used at that time no longer fit the advanced refractive error properly. Besides these clinical studies, the interval between two visual acuity tests in daily life can be 18 to 24 months. Longer intervals can also depend on the inability to make or visit an eye specialist appointment and the child's tolerance of blur. Children may only inform their parents after experiencing significant defocus. Many studies have shown that the more a child is exposed to blurred vision, the faster the rate of myopia progression.

[0011] Another common eye condition that is treated herein as a type of refractive error is presbyopia, which is part of the normal aging process and therefore will affect everyone eventually.

[0012] As the eye ages, it tends to focus light behind the retina instead of on it. As a result of insufficient accommodation, the ability to focus sharply on nearby objects gradually decreases. As a result, nearby objects appear blurry.

[0013] Detecting the progression of presbyopia and possibly tailoring the correction provided to the progression of presbyopia could potentially benefit millions of adults worldwide.

[0014] In the patent application EP 1 239 633 A1, it is proposed to adjust the power of the variable lens through the measurement of the refractive error of the user by an autorefractometer included in the device. However, this solution does not provide the desired effect in terms of detecting the change in refractive power, since the autorefractometer is not transparent and therefore cannot be worn continuously to perform continuous measurements. Furthermore, the use of objective measurements for refractive power measurement is known to be inaccurate, so that the refractive power provided by the variable lens may not perfectly correct the visual error of the user. This may lead to an increase in the refractive error rather than a reduction in the change in refractive power. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] International Publication No. 2018 / 213010 Brochure Summary of the Invention [Problem to be solved by the invention]

[0016] In this regard, there is a need to estimate in time the change in a person's refractive error and, depending on this change, to identify an updated refractive correction suitable for correcting the person's current refractive error. [Means for solving the problem]

[0017] An embodiment of the present invention provides a method for detecting variation in a person's current refractive error, the method comprising: a) obtaining an optical instrument including an optical lens, the optical lens having a refractive function adapted to correct a primary refractive error of a person, the optical instrument further including a processing circuit including a processor operatively connected to a memory; b) obtaining, using the memory, current values ​​of the parameters, the current values ​​being indicative of the variation of the person's current refractive error relative to the initial refractive error; c) detecting, using a processing circuit, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values ​​of the parameters; Includes.

[0018] "Refractive error" includes myopia, hyperopia, astigmatism, presbyopia, and any combination thereof. In the case of presbyopia, "refractive error" actually refers to a lack of accommodation.

[0019] Initial refractive error is to be understood as the refractive error at a reference point in time.

[0020] Current refractive error is to be understood as the refractive error at the present time, which is later than the reference time.

[0021] An embodiment of the present invention further provides a processing circuit including a processor operatively connected to the memory, the processing circuit configured to perform the above-mentioned method.

[0022] An embodiment of the present invention further provides an optical instrument comprising an optical lens, the refractive function of which is adapted to correct a person's primary refractive error, and a processing circuit as described above.

[0023] The optical instrument may further include one or more sensors adapted to obtain the current value of the parameter, and the processing circuitry may further include a communication interface with the one or more sensors.

[0024] An embodiment of the present invention further provides a computer program product accessible to a processor and comprising one or more stored sequences of instructions which, when executed by the processor, cause the processor to perform the steps of one of the methods described above.

[0025] An embodiment of the present invention further provides a storage medium or "memory" for storing one or more stored sequences of instructions for the computer programs described above.

[0026] The above-mentioned method, computer program, storage medium, processing circuit, sensor and optical device allow for detecting the variation of a person's current refractive error relative to an initial refractive error. This advantage is achieved in particular by the common feature of using a memory to obtain current values ​​of parameters, the current values ​​being indicative of said variation.

[0027] Thus, for example, a processing circuit integrated in the spectacles normally worn by a person can determine whether the refractive function of the optical lenses of the spectacles still matches the person's current refractive error and, if not, can determine an updated refractive function suitable to compensate for the person's current refractive error.

[0028] For example, as a result, changes in a child's myopia can be monitored and a refractive function suitable for compensating for said myopia can be updated, eliminating the need to schedule frequent visits to a clinician, while at the same time, correct assessment of the refractive power of the eye is simplified over known methods, as it is assessed without requiring any input from the child.

[0029] In one embodiment, the processor and memory are operatively connected to a first sensor adapted to measure a value of the parameter when the optical device is worn by the person, and the method includes: - measuring a current value of said parameter using a first sensor, the optical device being worn by the person; Further includes:

[0030] The first sensor allows for an in situ assessment of changes in the person's refractive error, and the optical instrument is therefore an independent device capable of assessing said changes.

[0031] In an embodiment, the first sensor is adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation of the person's current refractive error relative to an initial refractive error.

[0032] Measuring or monitoring physiological parameters of the person wearing the optical device provides objective values ​​that are collected and analyzed to estimate changes in the person's refractive error.

[0033] In one embodiment: - the first sensor is a squint motion sensor; - the physiological parameter being the occurrence of squinting in a person wearing the optical device; - measuring the current value of said parameter comprises detecting, using a squinting motion sensor, the occurrence of a squinting motion by a person wearing the optical instrument.

[0034] The squint sensor is non-invasive and can record indicators that indicate that the optical device wearer's current vision may be blurred. Recording such indicators can be useful, for example, to detect a decline in a child's vision even if the wearer does not actively identify this decline.

[0035] In one embodiment: - the first sensor includes at least one electrode configured for electroencephalography; - each of the at least one electrode is positioned to contact the person's forehead or the occipital region of the head when the optical device is worn by the person; - the physiological parameter is the electrical activity of the brain of the person wearing the optical device; - measuring the current value of said parameter comprises analysing, using at least one electrode, electrical activity of the brain of a person wearing the optical device.

[0036] Electroencephalography electrodes are non-invasive and are already present in some commercially available head-mounted accessories for various purposes. By recording and analyzing electroencephalograms over a period of time, neuronal activity can be detected and a high incidence of neuronal activity, i.e. a higher number of occurrences of neuronal activity in a certain viewing situation, can be associated with the perception of increased accommodation or blur by the person wearing the optical device, said increased accommodation or blur being an indication that the person's current refractive error has changed with respect to the initial refractive error.

[0037] In one embodiment, - the memory stores at least one indicator of a reference viewing condition; - the optical instrument further comprises at least one second sensor adapted to measure said viewing condition parameters when the optical instrument is worn by the person; - obtaining, by at least one second sensor, at least one indication of current viewing conditions; - detecting a variation of the person's current refractive error with respect to the initial refractive error is further based on a comparison of at least one indicator of the current viewing conditions with at least one indicator of the reference viewing conditions.

[0038] The reference viewing conditions allow one to put measurements from a first sensor into perspective by comparing them only if they correspond to similar viewing situations detected by a second sensor.

[0039] In one embodiment, the at least one second sensor is a lighting conditions sensor and the viewing conditions parameter is indicative of the light intensity of the scene seen by the person through the active refractive lens while the first sensor is measuring a current value of the parameter.

[0040] By measuring the light intensity of the scene, a bright atmosphere can be detected, where for example squinting may be independent of changes in refractive error.

[0041] In one embodiment, the at least one second sensor is a distance sensor, and the viewing condition parameter indicates the distance between the active refractive lens and an object that the person is viewing through the active refractive lens while the first sensor is measuring the current value of the parameter.

[0042] In this way, it is possible to determine whether the person wearing the optical device is currently viewing at a distance, intermediate or near distance. Any measurement by the first sensor at the current time can therefore be associated with a distance, intermediate or near viewing activity. Thus, changes over time, for example squinting or brainwaves, can be determined, particularly during near, intermediate or distance viewing activities. Changes in a particular eye anomaly can therefore be precisely monitored by selecting only measurements from the first sensor during viewing activities corresponding to a particular viewing distance.

[0043] In one embodiment, the optical lens is an active refractive lens and the method comprises: using the processing circuitry to generate an alert to the person if the detected variation exceeds a predetermined threshold. Further includes:

[0044] The alert may allow the person to control the active refractive lens to adjust the correction to suit their needs.

[0045] An embodiment of the present invention further provides a method for correcting refractive error in a person, comprising: a) obtaining an optical device including an active refractive lens, the refractive function of which is adapted to correct a primary refractive error of a person, the optical device further including a processing circuit including a processor operatively connected to a memory and a communication interface with the active refractive lens; b) obtaining, using the memory, current values ​​of the parameters, the current values ​​being indicative of the variation of the person's current refractive error relative to the initial refractive error; c) using the processing circuitry to detect a variation in the person's current refractive error relative to the initial refractive error based on the current values ​​of the acquired parameters; d) using the processing circuitry to adjust the refractive function of the active refractive lens if the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens if the detected variation is less than or equal to the predetermined threshold. Includes.

[0046] An embodiment of the present invention provides a processing circuit including a processor operatively connected to a memory and a communication interface with an active refractive lens, the processing circuit being configured to perform the above-mentioned method for correcting refractive error of a person.

[0047] An embodiment of the present invention further provides an optical instrument comprising an active refractive lens and a processing circuit as previously described. The optical instrument may further comprise one or more sensors adapted to obtain said current value of a parameter, and the processing circuit may further comprise a communication interface with said one or more sensors.

[0048] An embodiment of the present invention further provides a computer program comprising one or more stored sequences of instructions accessible to a processor and which, when executed by the processor, causes the processor to perform the steps of the above-mentioned method for correcting refractive error of a person.

[0049] An embodiment of the present invention further provides a storage medium or "memory" for storing one or more stored sequences of instructions for the computer programs described above.

[0050] The above-mentioned method for correcting a person's refractive error, the computer program therefor, the storage medium, the processing circuit and the optical device all make it possible to automatically drive an active refractive lens to correct a person's refractive error, or accommodation, taking into account changes in said refractive error over a period of time, so that the person always obtains the correct correction, even if his or her refractive error changes, and does not need to undergo eye examinations at an ophthalmologist.

[0051] In one embodiment, the optical instrument includes one or more sensors, the processing circuit includes a communication interface with the one or more sensors, the communication interface operatively coupled to the processor and the memory, and obtaining the current value of the parameter includes measuring the current value of the parameter using the one or more sensors.

[0052] In one embodiment, the steps of measuring or obtaining current values ​​of said parameters and detecting variation in the person's current refractive error relative to their initial refractive error are repeated over a period of time.

[0053] Thus, changes in the person's current refractive error are monitored over a period of time, so that changes in the current refractive error relative to the initial refractive error can be detected as soon as possible after said changes occur, and it is therefore possible to warn that the person's refractive error has changed, or to directly correct the current refractive error.

[0054] In one embodiment, adjusting the refractive function of the active refractive lens includes adjusting one or more of a spherical component, a cylindrical component, an axial component, an addition, and a prismatic component.

[0055] Adjusting the spherical component allows for myopia / hyperopia correction. Adjusting the cylinder and / or axis allows for astigmatism correction. Adjusting the add allows for presbyopia correction.

[0056] Prismatic adjustments allow compensation for alignment problems that may have gone undetected in the past or that may have been induced by optical power changes in the active refractive lens.

[0057] In one embodiment, the method comprises: - obtaining, using the memory, a predictive model of the variation of the person's refractive error over a period of time; - using a processing circuit to predict current values ​​of the parameters based on the predictive model; Includes.

[0058] For example, the optical instrument may include a sensor, the current value of the parameter may be repeatedly measured by the sensor over a period of time to form a database, and a predictive model may be established based on this database to predict future measurement results.

[0059] By predicting future measurements, future measurements can be double-checked and, for example, sensor failures can be detected and indicated.

[0060] Alternatively, the optical device may not have a sensor for measuring the refractive error over time, and the predictive model stored in the memory may be based on sociological data. For example, the predictive model may be obtained based on a record of the change in refractive error over time for a human population, in which case the predictive model is also collaborative. Such a predictive model allows to anticipate the change in refractive error and always provides an up-to-date correction, even without measuring the refractive error over time.

[0061] For a better understanding of the description provided herein and the advantages thereof, reference is now made to the following brief description, which should be read in conjunction with the accompanying drawings and detailed description, in which like reference numerals represent like parts. [Brief description of the drawings]

[0062] [Figure 1] 2 illustrates an example of a processing circuit adapted to carry out a method according to an embodiment of the present invention; [Diagram 2] 1 shows an example of a general flow chart of a method according to an embodiment of the invention for detecting the variation of a person's current refractive error. [Diagram 3] 1 shows an example of a general flow chart of a method according to an embodiment of the invention for correcting variations in a person's current refractive error. [Figure 4] 1 shows an example of a general flow chart of a method for detecting and correcting variations in a person's current refractive error according to an embodiment of the invention. [Diagram 5] 1 illustrates an example of an optical instrument according to an embodiment of the present invention. [Figure 6] 1 illustrates an example of an optical instrument according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] In the following description and drawings, the figures may not necessarily be drawn to scale, and certain features may be shown in generalized or schematic form for clarity and conciseness or for reference purposes. In addition, although the making and use of various embodiments are described in detail below, it should be understood that many inventive concepts are provided that may be embodied in various contexts, as described herein. The embodiments described herein are merely representative and do not limit the scope of the invention. It will also be apparent to those skilled in the art that all technical features defined for a process can be transferred, individually or in combination, to a system, and conversely, all technical features related to a system can be transferred, individually or in combination, to a process.

[0064]

[0023] Referring now to Figure 1, there is shown an example of a processing circuit according to an embodiment of the present invention, the processing circuit being adapted to perform a method for detecting and / or correcting variation in a person's current refractive error.

[0065] The processing circuitry includes a processor (PROC) operatively coupled to a memory (MEM).

[0066] In one embodiment of the present invention, the processing circuit further includes a communication interface (INT) operatively coupled to the processor (PROC).

[0067] The communication interface (INT) may be configured to communicate with one or more sensors (SENS).

[0068] The communication interface (INT) may be configured to communicate with one or more active refractive lenses (LENS).

[0069] The communication interface may be wired and / or wireless. Various types of wired and wireless technologies are available, the advantages of each of which are well known to those skilled in the art.

[0070]

[0023] Referring now to Figs. 2, 3 and 4, each shows an example of a general flow chart of a method according to an exemplary embodiment of the present invention, respectively: - detecting a variation in a current refractive error of a person based on current values ​​of parameters indicative of said variation ([Figure 2]); - detecting said variations and correcting them by adjusting the active refractive function of the active refractive lens (FIG. 3), as in the embodiment of FIG. 2; and - detecting said variations using a predictive model and correcting said variations by adjusting the active refractive function of the active refractive lens ([Figure 4]); Regarding.

[0071] According to each of the examples shown in [Figure 2], [Figure 3], and [Figure 4], an optical instrument is obtained: Obtain the instrument (S1).

[0072] The optical instrument includes an optical lens having a refractive function adapted to correct the primary refractive error of one eye of a person.

[0073] Of course, the optical instrument may comprise two optical lenses, the refractive functions of which are adapted to correct the primary refractive errors of both eyes of the person.

[0074] The optical instrument further includes processing circuitry as described above and shown in FIG.

[0075] The memory (MEM) stores a computer program executed by the processor (PROC). A general flow chart of the computer program is shown at least in FIG. 2, FIG. 3, and FIG. 4: - obtaining a current value of the parameter: obtain current value (S6), which is stored in a memory (MEM), the current value being indicative of the variation of the person's current refractive error relative to the initial refractive error; - detecting, by a processing circuit (CT) based on the current values ​​of the obtained parameters, a variation of said current refractive error of the person relative to said initial refractive error of the person: detecting variation (S7). Includes.

[0076] The variation of a person's current refractive error relative to their initial refractive error can relate to monocular or binocular refractive errors.

[0077] Various possibilities for obtaining (S6) the current value of a parameter may be implemented, which are explained below.

[0078] For example, said current value of a parameter may be measured directly by a first sensor (SENS) integrated within the obtained optical instrument and stored in a memory (MEM).

[0079] For example, said current value of the parameter may be indirectly determined by the processing circuit (CT) from measurements made by at least one first sensor (SENS) integrated in the optical instrument, the measurements being stored in the memory (MEM).

[0080] For example, the current value of the parameter may be indirectly determined by the processing circuit (CT) from a combination of measurements by at least one first sensor (SENS) and at least one second sensor, both integrated in the optical instrument, and the measurements are stored in the memory (MEM). For example, a combination of measurements of gaze distance, ambient light flux, and eyelid opening may predict a change in the person's refractive error.

[0081] For example, the current value of a parameter may be determined by a processing circuit (CT) from a derived predictive model.

[0082] Reference is now made to the exemplary embodiment shown in FIG. - the obtained optical instrument comprises one or more first sensors adapted to measure said current value of a parameter, the obtained optical instrument further comprises one or more sensors adapted to measure current viewing conditions, - the current value of the parameter is obtained based on input from at least one or more first sensors integrated in the obtained optical instrument: obtain current value (S6); - A variation of the person's current refractive error relative to the initial refractive error is detected based on at least the current values ​​of the obtained parameters: detect variation (S7).

[0083] At least one first sensor (SENS) is commanded by the processing circuit (CT) to measure a current value of a parameter: MEASURE CURRENT VALUE (S2). The current value thus obtained is transmitted to the processing circuit (CT) and stored in the memory (MEM).

[0084] In an embodiment, the step of measuring a current value of a parameter: Measuring a current value (S2) relates to directly measuring the variation of a person's current refractive error relative to their initial refractive error.

[0085] The current value of the parameter may be recorded, for example, by a first sensor, which includes a combination of one or more infrared (IR) light sources, such as light emitting diodes (LEDs) emitting light at 860 nm, mounted on the temple of the optical instrument, and an IR sensor mounted on the optical instrument, such as a camera sensitive in the IR light range and focused to capture a sharp image of a person's eye. Each IR sensor is in the vicinity of a corresponding IR light source and measures the IR light emitted by the IR light source and reflected on the observer's sclera.

[0086] The optical instrument may further include a reflective element, for example a holographic mirror on the back surface of the refractive lens, designed to reflect the light incident from the IR light source towards the eye. Preferably, the reflective element is such that the light rays incident on the eye are collimated so that they enter the pupil of the eye parallel, although this configuration is not required and the light can also be diverging or converging (e.g. +-3D).

[0087] According to the general principle of decentered photorefraction, emitted light enters the eye, reaches the retina, and is then reflected by the retina towards a reflective element and then reflected back to the camera to obtain an image of the person's eye. In the obtained image, a crescent of light is seen above the person's pupil. The size of the crescent of light depends on the person's refractive error.

[0088] In an embodiment, the step of measuring a current value of a parameter: measuring the current value (S2) relates to detecting behavioral and / or physiological changes that may be induced by blurred vision.

[0089] In an embodiment, the detected behavioral and physiological blur-induced changes are indicative of electroencephalographic variability.

[0090] Indeed, it is well known that decision-making is primarily carried out in the frontal regions of the brain. When distance vision becomes more difficult with increasing blur, brain activity patterns change.

[0091] Referring now to FIG. 5, there is shown an example of an optical instrument that has been acquired to record a person's brain activity patterns over a period of time.

[0092] The resulting optical instrument 100 includes two optical lenses 200 mounted in a spectacle frame and further includes a first sensor 300. The first sensor 300: - two dry electroencephalography (EEG) sensors 330 placed on the frame of the optical device so as to be in contact with the skull region near the forehead when the optical device 100 is worn by the person, and optionally - two dry EEG sensors 340 placed at the ends of the eyeglass temples to record brain activity in the primary visual cortex when the optical device 100 is worn by the person; Includes.

[0093] The resulting optical instrument 100 further includes one or more second sensors 400 for measuring additional parameters related to the wearer and / or current vision.

[0094] These sensors can record cortical activity for various visual tasks, either continuously or for a few minutes at different times of the day. The recorded cortical activity can be analyzed, for example using algorithms based on the principles of deep learning, to provide feedback on the level of defocus (i.e., "blurring") experienced by the wearer in real time or at the end of the day. Optionally, it may be envisaged to generate a behavioral baseline based on the recorded cortical activity over a period of time, which represents the wearer's usual visual habits based on optimal vision correction, and to use the generated behavioral baseline as an indicator of whether current measurements of cortical activity indicate that defocus experiences are currently occurring. For example, brain activity signals recorded during the days and weeks following the last eye examination and wearing of a new device can be used as a baseline.

[0095] For near vision, the cortical signal of blurred vision can be used as feedback to force the individual, e.g., a child, to adjust correctly on the reading plane. For distance vision activities, the cortical signal of blurred vision can indicate as feedback that myopia has progressed since the last eye exam and that the individual should be provided with new glasses. This feedback can be provided at the end of each day, every other day, every week, etc.

[0096] In an embodiment, the detected blur-induced behavioral and physiological changes are indicative of a tendency to squint.

[0097] By squinting, the size of the pupil can be voluntarily reduced. This action is used, for example, to protect against bright, glaring light by reducing the amount of light entering the eye. It is also well known that squinting can help an observer see better when they are optically unable to focus. In fact, narrowing the palpebral fissure reduces the pupil diameter and improves the depth of focus. An increased occurrence of squinting during a distance viewing task is a good marker of myopia progression. As myopia progresses, the image is no longer perfectly focused on the retina. Thus, a person with advanced myopia, which is undercorrected, will squint more frequently to reduce the level of blur and allow them to read objects at a distance. Using big data statistics and / or deep learning principles, an increased tendency to squint can be detected in visual situations that should not require such behavior, i.e., in the case of myopic patients, in distance vision and normal lighting conditions, or in the case of hyperopic or presbyopic patients, in near vision and normal lighting conditions.

[0098] Referring now to FIG. 6, an example of the resulting optical instrument is shown adapted to record changes in squinting tendency over time.

[0099] The resulting optical instrument 100 includes two optical lenses 200 mounted in an eyeglass frame and further includes a first sensor 300. The first sensor 300 includes a combination of one or more IR LEDs 310 located within the temples of the optical instrument and one or more IR sensors 320 located on the optical instrument that measure IR light emitted by the IR LEDs and reflected off the viewer's sclera. An overall decrease in reflected IR light indicates an increased tendency to squint.

[0100] Alternatively, an electromyography (EMG) sensor may be placed on the portion of the eyewear device that contacts the temples close to the person's eyes. The EMG sensor may therefore record an increase in strength of the eyelid muscles, which indicates an increased tendency to squint.

[0101] Thus, if it is detected that the person's tendency to squint increases under normal lighting conditions for distance vision activities, it can be concluded that the person's current vision correction is no longer adequate, that his / her myopia is progressing, and that new vision correction is required.

[0102] As a result of the step of measuring the current value of the parameter using any of the first sensors described above in relation to [Figures 2] and [Figure 3]: Measure Current Value (S2), a step of obtaining the current value of the parameter: Obtain Current Value (S6) is realized, which is stored in memory (MEM).

[0103] The stored current values ​​of the parameters can be directly interpreted for a step of detecting variation in a person's current refractive error: Detect Variation (S7).

[0104] However, the current values ​​of the parameters can be better interpreted if said current values ​​are reliably related to the current wearer state (e.g. head posture and / or eye gaze direction and / or viewing distance, etc.) and to the current environmental conditions (e.g. lighting conditions and / or time of day, etc.). By relating the recording to the current wearer or environmental conditions, it becomes possible to compare any obtained recording with a recording obtained previously under similar wearer or environmental conditions. Any detected deviations can therefore be interpreted as relating only to variations in the refractive power of the user's eyes.

[0105] A variety of sensors may be used, and the examples provided and described in detail above are non-limiting. It should also be noted that although the foregoing examples relate to identifying changes in myopia, each may also be applicable to other types of visual impairments, such as presbyopia, hyperopia, astigmatism, etc.

[0106] With myopia, people may squint during distance viewing activities because they cannot see clearly in the distance, but not during near viewing activities.

[0107] In the case of presbyopia or hyperopia, people may squint during near viewing activities if they have accommodation problems, but not during far viewing activities. Age may be additional information that allows for the distinction between hyperopia and presbyopia. For example, a person who squints during near viewing activities may be considered hyperopic if their age is, for example, less than 40 or 45 years old, otherwise presbyopic.

[0108] With astigmatism, people squint because they cannot see clearly regardless of viewing distance.

[0109] In an embodiment, the obtained optical instrument comprises at least one second sensor adapted to obtain a current viewing condition. The at least one second sensor (SENS) is instructed by the processing circuit (CT) to obtain the current viewing condition: obtain viewing condition (S3). The current viewing condition thus obtained is transmitted to the processing circuit (CT) and associated with the stored current value of the parameter and stored in the memory (MEM).

[0110] The viewing conditions may relate to the wearer (wearer-related viewing conditions or "observer conditions") or to the wearer's environment (environment-related viewing conditions or "environmental conditions").

[0111] For example, a sensor such as a telemeter may be used to inform about viewing distance so that the processing circuitry may determine whether the wearer is performing a distance or near viewing activity. Such viewing distance sensors may be used, for example, in combination with a brain activity recording sensor to optimally analyze changes in brain activity over time to identify, for example, whether the person is experiencing blurring in distance viewing activities.

[0112] Furthermore, by knowing whether a person is performing a far or near viewing activity, it is possible to determine whether the recorded changes in the refractive power of the person's eye are, for example, induced by myopia progression or induced by accommodation. Thanks to this telemetry device, together with the continuous recording of the changes in the refractive power of the person's eye, statistics of the accommodative response can be obtained, informing of possible loss of accommodation in near vision. Many studies have demonstrated that the greater the loss of accommodation, the faster the progression of myopia. These statistics of the accommodative response can be used to detect the risk of myopia progression early, even before myopia actually progresses.

[0113] Besides helping to identify the progression of a wearer's refractive error, such a sensor may also be useful for checking whether the refractive error is well corrected during various prolonged daily activities.

[0114] For example, a camera pointed at the wearer's eye may detect the wearer's gaze direction. The resulting gaze direction may be associated with a gaze distance estimated by the processing circuitry using an ergorama. For example, a downward gaze direction may be associated with near vision. For example, a gaze direction straight ahead may be associated with far vision.

[0115] For example, a light intensity sensor may be used to provide the processing circuit with an indication of the lighting level of the wearer's environment.

[0116] For example, an accelerometer may be used in conjunction with a distance sensor, and in one example, the glasses may be tilted to indicate a short distance. The processing circuit may determine that the wearer is engaged in a reading activity based on such a composite indicator. Conversely, if the glasses are not currently tilted and the gaze distance corresponds to far-sightedness, the processing circuit may determine that the wearer is engaged in an activity related to far-sightedness.

[0117] Based on the stored current viewing conditions, from among multiple and / or consecutive records of parameter values, those records corresponding to similar wearer preparatory environmental conditions can be specifically selected.

[0118] Such a sensor is particularly relevant in combination with a squinting behavior sensor (as squinting behavior may depend on lighting levels).

[0119] The current viewing conditions obtained using any of the second sensors already described with respect to [Figures 2] and [Figure 3]: Acquire viewing conditions (S3) and stored in a memory (MEM), together with the current values ​​of the stored parameters, can be interpreted to detect variations in a person's current refractive error: Detect variations (S7).

[0120] Detect the variation of the current refractive error of the person relative to the initial refractive error of the person: Detect variation (S7) Various possibilities can be implemented.

[0121] For example, the current values ​​of the obtained parameters may be compared to predefined thresholds. Such a comparison may be useful for monitoring the continuous change in the person's refractive error. For example, such a comparison may indicate whether the person's current refractive error remains within an acceptable range around the initial refractive error.

[0122] For example, a current value of a parameter may be obtained repeatedly over a period of time. Variations in the current value of the parameter over time may be compared to a predetermined threshold. Such a comparison may indicate, for example, a sudden and unexpected change in the person's refractive error.

[0123] For example, the change in the refraction of the person's eye can be determined based on multiple / successive recordings selected from a larger number of different recordings, which represent similar wearer and environmental conditions. Such determination allows to compare only those recordings corresponding to situations that represent a change in a certain refractive error, which overcomes the accuracy problem of obtaining a precise refractive change, and also saves memory and processing resources by considering only relevant measurements from any first sensor incorporated in the obtained optical device. For example, in the case of myopia, only the measurements from the first sensor during distance viewing activities need to be considered. For example, in the case of presbyopia, only the measurements from the first sensor during distance viewing activities need to be considered.

[0124] In an embodiment, detecting a variation of the person's current refractive error relative to the initial refractive error: after detecting the variation (S7), the processing circuit (CT) generates an alert to the person or a third party.

[0125] An alert may be provided to indicate the detected variation and may be used, for example, to order new optical equipment or to schedule an appointment with an eye specialist.

[0126] In an embodiment, detecting a variation of the person's current refractive error relative to the initial refractive error: based on detecting the variation (S7), the processing circuit (CT) issues a signal for adjusting the corrective power of at least one optical lens of the optical instrument to compensate for said detected variation.

[0127] The signal may for example be a warning signal intended to provide a visual or audio warning to the person wearing the optical device, so that he or she manually adjusts the correction power.

[0128] Alternatively, the signal may be a command signal for automatically adjusting said correction power.

[0129] Now, referring to Figure 3: - a variation of the person's current refractive error relative to the initial refractive error is detected, according to any of the embodiments described above with reference to [fig. 2]: detect variation (S7), at least one optical lens of the resulting optical device is an active refractive lens, - The detected variation of the person's current refractive error relative to the initial refractive error is used to adjust the correction provided by the active refractive lens to compensate for said detected variation: an adjustment (S8).

[0130] Of course, the steps of detecting: detecting the variation (S7) and adjusting: adjusting (S8) can be repeated indefinitely, thereby repeatedly / continuously providing the person with up-to-date corrected powers.

[0131] In one embodiment of the invention, the resulting optical instrument is a smart glass, which comprises: - Two active refractive lenses; - at least one first sensor adapted to measure a current value of a parameter indicative of the variation of a person's current refractive error relative to his / her initial refractive error; at least one second sensor adapted to measure current viewing conditions; - a computer system for executing the method shown in [fig.3]; Includes.

[0132] An active refractive lens is an optical lens that exhibits a total lens correction power that can be described as a combination of a first lens correction power made for central vision correction and a second lens correction power that is active (in other words, controllable) and provides an individual with additional central or peripheral vision correction.

[0133] The first lens correction power can be passive or active and is usually initially matched to the initial refraction, for example the first lens correction power is equal to the prescription prescribed by an ophthalmologist for a person.

[0134] Active correction can be achieved by a variety of techniques.

[0135] In the wide field Alvarez lens, two plates can be brought together and slid relative to one another. Depending on the relative position of both plates, different correction powers are obtained. The actuation can be performed manually by various commands (e.g. slider, roller, etc.). In this case, the person can be informed via any kind of human-machine interface (HMI) (directly on the optical device, via an application, via a warning on a terminal such as a smartphone, etc.) when the compulsion power must be changed and how much correction power to add. The actuation can be performed automatically via an electrically driven motor. In this case, the required correction power can be changed directly and communicated to the wearer.

[0136] In a wide field fluid lens, the shape of the fluid-filled cavity is controlled to provide a variety of corrective powers.

[0137] For example, the optical device may include a pump to control the amount of liquid in a cavity, perhaps enclosed between two ophthalmic shells and fabricated on one side with an elastic membrane. When fluid is injected into the cavity, the elastic membrane deforms, thereby changing the power of the lens.

[0138] For example, the lens may include a cavity containing a fluid, possibly enclosed between two ophthalmic shells. The cavity is fabricated with an elastic membrane. The optical device may further include mechanical actuators distributed along the deformable ring and holding the membrane in tension. The mechanical actuators deform the deformable ring at several points, thereby deforming the membrane and changing the power of the lens.

[0139] For example, the lens may include an assembly of a first cavity filled with a first liquid having a first refractive index and a second cavity filled with a second liquid having a second refractive index different from the first refractive index, and an elastic membrane as a partition between the first and second cavities. The assembly may be enclosed within an ophthalmic shell, for example having a refractive index close to the first refractive index. The optical device may further include a reversible pump for adjusting the relative amounts of the first and second liquids to deform the elastic membrane.

[0140] In any kind of wide field fluid lens, this can be done manually by various commands (e.g. slider, roller, etc.). In this case, the person can be informed when the correction power should be changed and how much correction power to add via any kind of human-machine interface (HMI) (directly on the optical instrument, via an application, via an alert on a terminal such as a smartphone, etc.). The actuation can be automatic via an electrically driven actuator or pump. In this case, the required correction power can be changed directly and communicated to the wearer.

[0141] Other technologies of active refractive lenses can also be used, such as liquid crystal electro-optic lenses, which contain liquid crystals arranged according to a pixelated matrix. Each liquid crystal can be controlled to provide a specific power correction. Liquid crystal electro-optic lenses provide finely controlled optical designs. The actuation can be automatic via an electrically actuated active / passive matrix. In this case, the required power of correction can be directly changed and communicated to the wearer.

[0142] The refractive function of each active refractive lens is initially set to correct the initial refractive error, if any, of a person based on the initial refractive power of the person's eye. The initial refractive power may be obtained by performing any standard or known power specification process.

[0143] A step of adjusting the correction power provided by the active refractive lens to compensate for the detected variations: The adjustment (S8) allows always providing an appropriate correction for persons with ever-changing refractive errors detected based on measurements over a period of time by the first sensor and, optionally, the second sensor.

[0144] The optical device therefore provides a correction that is tailored to the individual in that any changes in the individual's refractive error relative to the initial refractive error are taken into account.

[0145] Various variants of the concept as described above may be recognized, in particular the optical instrument obtained may not include any sensor and may not include any measurements collected over a period of time to assess changes in a person's refractive error and provide corrections that take this change into account.

[0146] Now referring to FIG. 4, the resulting optical instrument includes at least one active refractive lens and a processing circuit (CT). This implementation can be cost-effective and weight-effective since the optical instrument does not need any sensors.

[0147] A prediction model of the change in the person's refractive error over a period of time is obtained by the processing circuit (CT): get model (S4). For the myopia prediction model, the input parameters can be selected from, but are not limited to, age, race, sex, and previous ECP measurement prescription (including sphere, cylinder, or mean sphere). For the presbyopia prediction model, the input parameters can be selected from, but are not limited to, age, sun exposure habits, and previous ECP measurement prescription (including sphere, cylinder, or mean sphere, and add).

[0148] In an embodiment, the current value of the parameter indicative of the variation of the person's current refractive error relative to his / her initial refractive error is predicted by the processing circuit (CT): Predict Current Value (S5).

[0149] The step of predicting the current value may be performed based on the obtained prediction model.

[0150] The current value of the parameter indicative of the variation of the person's current refractive error relative to the initial refractive error may therefore be obtained based on a stored predictive model rather than on measurements: Obtain Current Value (S6).

[0151] A variation in the person's current refractive error relative to the initial refractive error may be detected based on the obtained current values ​​of the parameters.

[0152] The detected variation of the person's current refractive error relative to the initial refractive error is used to adjust the correction power provided by the active refractive lens to compensate for said predicted variation: adjustment (S8).

[0153] The optical device therefore provides a correction that is tailored to the individual, taking into account any changes in that individual's refractive error relative to the initial refractive error.

[0154] The embodiments described above with respect to [FIG. 2] and [FIG. 4], respectively, may be combined with each other.

[0155] In particular, the predictive model described above with respect to FIG. 4 may be combined with measurements from a first sensor and, optionally, from a second sensor described above with respect to FIG.

[0156] Indeed, the predictive model can be improved and personalized to the individual using collected data from repeated direct measurements of the person's change in refractive error over a period of time. If the measurement of change in refractive error is obtained indirectly by combining measurements obtained from the first and second sensors, the quality of predictions from the predictive model can also be improved by combining said measurements using collected data from repeated measurements using the first and second sensors over a period of time. [Explanation of symbols]

[0157] 100 Optical equipment 200 Optical Lenses 300 First Sensor 310 LED 320 IR Sensor 330 Dry Electroencephalography (EEG) Sensor 340 Dry EEG Sensor 400 Second Sensor

Claims

1. accessible to a processor and, when executed by the processor, causing the processor to:

1. A method of refractive error variation based monitoring and alerting, comprising: The method includes using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of the person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method including: using said memory to obtain current values ​​of parameters, said current values ​​being indicative of a variation of said person's current refractive error relative to said initial refractive error; detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values ​​of the parameters; using said processing circuitry to generate an alarm if the detected variation exceeds a predetermined threshold; - using said memory to obtain a predictive model of the variation of the refractive error of said person over a period of time; - using said processing circuitry to predict said current values ​​of said parameters based on said predictive model; Including, The processor and the memory are operatively connected to a first sensor adapted to measure a value of the parameter when the optical instrument is worn by the person, the method comprising: - measuring the current value of said parameter using said first sensor, said optical instrument being worn by said person; a computer program comprising one or more stored instruction sequences for causing said steps of the method further comprising:

2. 2. The computer program product of claim 1, wherein the first sensor is a physiological sensor adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation of the person's current refractive error relative to the initial refractive error.

3. - said first sensor is a squint motion sensor; - the physiological parameter is the occurrence of squinting movements of the person wearing the optical instrument, 3. A computer program product as claimed in claim 2, wherein the step of measuring the current value of the parameter comprises the step of detecting, using the squinting sensor, the occurrence of a squinting movement of the person wearing the optical instrument.

4. - said physiological sensor comprises at least one electrode configured for electroencephalography; - each of said at least one electrode is arranged to be in contact with the forehead or the occipital region of said person when said optical device is worn by said person; - said physiological parameter is the electrical activity of the brain of said person wearing said optical instrument, - measuring the current value of the parameter comprises analyzing, using the at least one electrode, the electrical activity of the brain of the person wearing the optical device; 3. A computer program according to claim 2.

5. - said memory stores an indication of a reference viewing condition; said optical instrument further comprises at least one second sensor adapted to measure a viewing condition parameter when said optical instrument is worn by said person; - obtaining, by said second sensor, an indication of current viewing conditions, the step of detecting a variation of the person's current refractive error with respect to the initial refractive error is further based on a comparison of the indication of the current viewing conditions with an indication of the reference viewing conditions, 2. The computer program product of claim 1.

6. 6. The computer program product of claim 5, wherein the optical lens is an active refractive lens, the first sensor is a physiological sensor adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation of the person's current refractive error relative to the initial refractive error, and the at least one second sensor is a lighting condition sensor, the viewing condition parameter being indicative of the light intensity of a scene seen by the person through the active refractive lens while the physiological sensor is measuring the current value of the physiological parameter.

7. 6. The computer program product of claim 5, wherein the optical lens is an active refractive lens, the first sensor is a physiological sensor adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation of the person's current refractive error relative to the initial refractive error, and the at least one second sensor is a distance sensor, and the viewing condition parameter is indicative of a distance between the active refractive lens and an object that the person is viewing through the active refractive lens while the physiological sensor is measuring the current value of the physiological parameter.

8. The computer program product of claim 1 , wherein the steps of measuring the current value of the parameter and detecting the variation of the person's current refractive error relative to the initial refractive error are repeated over a period of time.

9. accessible to a processor and, when executed by the processor, causing the processor to:

1. A method for adjusting a refractive function of an active refractive lens, comprising: The method includes using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of the person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method including: using said memory to obtain current values ​​of parameters, said current values ​​being indicative of a variation of said person's current refractive error relative to said initial refractive error; detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values ​​of the parameters; using the processing circuitry to adjust a refractive function of the active refractive lens when the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens when the detected variation is less than or equal to the predetermined threshold; a computer program comprising one or more stored instruction sequences for causing said steps of the method to be performed, said computer program comprising:

10. 10. A storage medium storing one or more stored instruction sequences of the computer program of claim 9.

11. A processing circuit including a processor coupled to a memory, 1. A method of adjusting a refractive function of an active refractive lens, the method comprising using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of a person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method comprising: using said memory to obtain current values ​​of parameters, said current values ​​being indicative of a variation of said person's current refractive error relative to said initial refractive error; detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values ​​of the parameters; using the processing circuitry to adjust a refractive function of the active refractive lens when the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens when the detected variation is less than or equal to the predetermined threshold; A processing circuit configured to perform the method.

12. 1. An optical instrument comprising an optical lens and a processing circuit, the processing circuit including a processor coupled to a memory, the processing circuit comprising:

1. A method of adjusting a refractive function of an active refractive lens, the method comprising using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of a person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method comprising: using said memory to obtain current values ​​of parameters, said current values ​​being indicative of a variation of said person's current refractive error relative to said initial refractive error; detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values ​​of the parameters; using the processing circuitry to adjust a refractive function of the active refractive lens when the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens when the detected variation is less than or equal to the predetermined threshold; 13. An optical instrument configured to perform a method comprising:

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