Optical lens and method for enhanced visual perception

Abstract

The present invention relates to an optical lens for enhanced visual perception of a scene comprising a bandpass filter or a blur filter to reduce contrast and high spatial frequency of the scene.

Description

Technical Field

[0001] The present invention relates to optical lenses and methods for enhanced visual perception, as well as ophthalmic lenses and spectacles. Background Art

[0002] In the human retina, photoreceptor cells are responsible for visual phototransduction, which is the process by which light is absorbed by pigment molecules present in the photoreceptor cells and then converted into electrical signals.

[0003] There are two types of photoreceptors: rods and cones. Cones are divided into three categories based on their spectral sensitivity to light: short-wavelength-sensitive cones (or S-type cones), medium-wavelength-sensitive cones (or M-type cones), and long-wavelength-sensitive cones (or L-type cones).

[0004] Cones are responsible for photopic and color vision, while rods are responsible for scotopic vision.

[0005] Information from cones is transmitted to the brain by two main types of neurons with complementary properties: magnocellular neurons and parvocellular neurons.

[0006] In the brain, visual information is processed by brain areas organized into two major anatomical streams: the ventral stream, which is primarily involved in the perception of color and shape, and the dorsal stream, which is primarily involved in visual perception, processing of motion, and processing of the spatial properties of objects (their location, orientation) for visually guided actions.

[0007] Colored sheets superimposed on a reading surface (e.g., on a paper or book) have been proposed as a means of facilitating reading. However, these colored sheets do not provide light filtering properties suitable for favoring processing through one visual stream or another of the subject. Furthermore, because the choice of sheet is arbitrary, based on subjective statements or personal preferences of the subject, there is no evidence or suggestion that such sheets are beneficial for dyslexia.

[0008] Furthermore, these colored sheets can only be used when reading on a fixed reading surface, which is not compatible with most daily life activities.

[0009] In this area, there are also reading glasses. Reading glasses provide vision correction to compensate for the decreased vision due to aging. However, they also fail to provide a satisfactory improvement in visual perception. Summary of the invention

[0010] It is an object of the present invention to overcome some or all of the disadvantages of the prior art and to improve the effectiveness of visual aids to reading, particularly for dyslexics and / or individuals with macrocellular flow defects.

[0011] It is also an object of the present invention to develop a visual aid which improves visual processing in the magnocellular stream and thereby improves dorsal stream visual functions, such as the perception of moving or rapidly changing stimuli.

[0012] To this end, the subject of the invention is an optical lens and a method for enhanced visual perception of motion.

[0013] The present invention thus relates to an optical lens for enhanced visual perception of a scene. The optical lens has a first side configured to face an eye of a subject, and a second side opposite to the first side. The optical lens comprises:

[0014] • Bandpass filters with a central wavelength between 540nm and 560nm and a full width at half maximum equal to or less than 50nm; and / or

[0015] • A blur filter configured to attenuate spatial frequencies greater than 10 cycles / degree (cyc / deg) corresponding to the visual stimulus of the scene.

[0016] The bandpass filter and / or blur filter advantageously reduces contrast and high spatial frequencies of a scene viewed through the optical lens and suppresses parvocellular flow in a subject wearing the optical lens.

[0017] In an embodiment, the optical lens includes a bandpass filter and a blur filter. The combination of the two filters improves the suppression of small cell flow in the subject.

[0018] In an embodiment, the central wavelength of the bandpass filter is 545 nm to 555 nm, preferably equal to 550 nm. This particular wavelength range is where the absorption rate of human M-type cone cells and the absorption rate of human L-type cone cells are similar, that is, the wavelength range that minimizes the contribution of the small cell stream to vision and maximizes the contribution of the large cell stream to vision.

[0019] In an embodiment, the total transmittance of the bandpass filter is equal to or lower than 10%, preferably lower than 4%.

[0020] In an embodiment, the blur filter is configured to attenuate spatial frequencies corresponding to the visual stimulus of the scene greater than 8 cycles / degree, preferably greater than 6 cycles / degree, more preferably greater than 4 cycles / degree.

[0021] In an embodiment, the bandpass filter is laid on a first side of the optical lens and the blur filter is laid on a second side of the optical lens.

[0022] In an embodiment, the blur filter is made of a solid diffuse material, or of a solid material with a surface roughness, preferably roughened quartz or polytetrafluoroethylene.

[0023] In an embodiment, the optical lens is an ophthalmic lens, preferably a spectacle lens.

[0024] The invention also relates to spectacles comprising a frame and a pair of spectacles lenses as disclosed above.

[0025] The present invention also relates to a method for selecting an optical lens for improving a subject's visual perception of a scene, the method comprising:

[0026] a. providing the subject with the optical lens or glasses disclosed above, the optical lens or glasses being inserted between the subject's eyes and the scene at a predetermined distance from the subject's eyes and the scene;

[0027] b. measuring the optical parameters of the subject,

[0028] wherein said providing and measuring are repeated for at least two optical lenses or glasses having bandpass filters with different filtering characteristics and / or blur filters with different characteristics; and

[0029] c. Select the optical lens or glasses that corresponds to the best optical parameters measured among the optical lenses or glasses provided.

[0030] In an embodiment, the optical parameter is selected from the following list: reading efficiency (eg using an inverse efficiency index), visual motion direction perception threshold, visual motion speed perception threshold.

[0031] In an embodiment, the scene comprises a linear arrangement of symbols, numbers and / or letters. In fact, such scenes have been shown to be very difficult to read / discern for individuals with dyslexia. Therefore, the use of such scenes is particularly relevant to selecting the most appropriate lenses or glasses for individuals with dyslexia.

[0032] The invention also relates to a method for improving the perception of moving or transient visual stimuli, the method comprising inserting the optical lenses or glasses disclosed above between the eyes of a subject and the scene.

[0033] Finally, the present invention also relates to a method for treating damage to the magnocellular and / or parvocellular visual pathways in a subject, the method comprising inserting an optical lens or spectacles disclosed above between the subject's eyes and a visual stimulus. The method is particularly suitable for subjects suffering from dyslexia.

[0034] definition

[0035] In this disclosure, the following terms have the following meanings:

[0036] • "Approximately" is used herein to mean approximately, roughly, in the vicinity of, or in the region of. When the term "approximately" is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values. When the term "approximately" is used before a number, it refers to the value of the number plus or minus 10%.

[0037] • “Dyslexia,” also known as acquired dyslexia, refers to acquired reading difficulties, such as those caused by brain damage.

[0038] • A "blur filter" is a filter by which the perception of boundaries between objects in a scene - in other words, the edge or transition between two parts of a scene that provide different visual stimuli - is degraded. Typically, through a blur filter, the edges of objects are not perceived sharply, but appear diffuse or blurred, while the overall shape of the object remains perceptible. This is in Figure 4 It has been shown in Figure 4 B is blurred.

[0039] • "Cycles / degree" refers to the unit of spatial frequency: the number of times a pattern repeats within a 1 degree visual angle. For example, viewing a pattern consisting of 50 vertical lines regularly spaced 1 cm apart within a visual angle of approximately 28° and placed at a distance of 1 meter from the subject's eyes produces a visual stimulus with a spatial frequency of approximately 50 / 28 = 1.8 cycles / degree. The same pattern placed at a distance of 5 meters produces a visual stimulus with a spatial frequency of approximately 8.7 cycles / degree. Spatial frequency is not an intrinsic property of a scene, but a property of the visual stimulus corresponding to the scene.

[0040] • The "diffusion" of a lens refers to the property of the lens to scatter the light passing through it in directions other than the incident direction.

[0041] • “Dyslexia” refers to reading difficulties in subjects with adequate intelligence and, in some cases, retained vision. Some dyslexic individuals have magnocellular stream defects.

[0042] • "Frost filter" refers to a blur filter. Frost filters are often mentioned in commercial references, such as the diffuse filter provided by LEE Filters (a Panavision company).

[0043] • “Photostimulus” refers to the light that reaches the subject’s eye and causes a response (phototransduction) in the photoreceptor cells in the retina.

[0044] • The "refraction" of a lens refers to the property of a lens to deflect light passing through it in other directions (i.e. different from the incident direction).

[0045] • “Scenes” refer to physical objects observed by the patient, such as texts, symbols, or drawings, and more generally to the everyday environment.

[0046] • The "transmittance" of a lens is the ratio of light incident on one side of the lens to the light transmitted through the opposite side, for a predefined wavelength of light, or for light in general. Total transmittance is the average percentage of visible light transmitted through the filter, integrated over the entire visible spectrum.

[0047] • “Visual stimulus” refers to the light signals generated by the scene and received by the patient’s eyes.

[0048] • “Visual perception” refers to the subject’s ability to perceive visual stimuli (e.g., perceiving the color, shape, or motion of visual stimuli) through the corresponding light stimuli reaching the eyes. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic representation of an optical lens (1) according to the present invention;

[0050] Figure 2 is a graph showing exemplary absorbance spectra (absorbance 1 corresponds to 100% light absorption) of human M-type cone cells (solid line) and L-type cone cells (dashed line) as a function of the wavelength of light (in nm).

[0051] Figure 3 is a graph showing the transmittance spectrum (%) of a bandpass filter consistent with the present disclosure as a function of the wavelength of light (in nm).

[0052] Figure 4 is not used ( Figure 4 A) and use ( Figure 4 B) Photograph of text observed without blur filter 13 of the present invention.

[0053] Figure 5 is a graph showing the reading efficiency (the total number of words accurately read on the vertical axis) of a subject reading a text when not wearing any lens (None) and when wearing the optical lens 1 (the center wavelength of the bandpass filter 12 in nm).

[0054] Figure 6 is the text suitable for the alphabetic cross test. DETAILED DESCRIPTION

[0055] The invention relates to an optical lens 1 for enhanced visual perception.

[0056] Figure 1 is a schematic diagram of an optical lens 1 according to the present invention.

[0057] The optical lens 1 has a first side 10 configured to face an eye 2 of a subject, and a second side 11 opposite to the first side 10 .

[0058] The optical lens 1 includes a band pass filter 12 and a blur filter 13. Preferably, the optical lens 1 includes both the band pass filter 12 and the blur filter 13.

[0059] As will be explained later, each of these filters 12, 13 may be a film or a layer. In this case, the optical lens 1 has a layered structure including a substrate 14 on which the filters 12, 13 are laid.

[0060] For example, the bandpass filter 12 may be a colored film attached to the substrate 14. The blur filter 13 may be a thin sheet attached to the substrate 14, such as a polystyrene sheet.

[0061] Substrate 14 may be a non-corrective optical lens (eg, an optical lens of protective eyewear) or a corrective optical lens (eg, an ophthalmic lens made according to a prescription for a subject) or any material suitable for placement in front of eye 2 of a subject.

[0062] Bandpass filter

[0063] The central wavelength of the bandpass filter 12 is between 540 nm and 560 nm, preferably between 545 nm and 555 nm. In addition, the full width at half maximum (FWHM) of the bandpass filter 12 is equal to or lower than 50 nm.

[0064] More precisely, the central wavelength of the bandpass filter 12 is the wavelength corresponding to the maximum transmittance of the filter. Figure 3 The central wavelength of the bandpass filter 12 (as shown) is also the wavelength at the center of the curve.

[0065] The bandpass filter 12 is allowed to block all incident light wavelengths except for the incident light wavelengths belonging to the allowed frequency band of the filter, or to drastically attenuate all incident light wavelengths except for the incident light wavelengths belonging to the allowed frequency band of the filter.

[0066] Therefore, the light stimulus reaching the subject includes only the small range of wavelengths corresponding to those absorbed equally by the medium-wavelength-sensitive cones (also called M-type cones) and long-wavelength-sensitive cones (also called L-type cones) of the human retina.

[0067] The central wavelength selected within a small range of about 550 nm ensures that the bandpass filter 12 is centered on a wavelength located at the intersection between the absorbance spectra of the M-type cones and the L-type cones, ie, a wavelength that is equally absorbed by the M-type cones and the L-type cones.

[0068] Preferably, the central wavelength of the bandpass filter 12 is equal to 550 nm. In most subjects, this wavelength corresponds to the wavelength of the intersection between the absorption spectra of M-type cones and L-type cones.

[0069] In some embodiments, the central wavelength may be between 545 nm and 555 nm and may differ from 550 nm, for example if the subject exhibits corneal spectral sensitivity or M and L cone absorptivity spectra that vary slightly from the average.

[0070] Figure 2 is a graph showing typical absorption spectra of M-type cone cells (solid line) and L-type cone cells (dashed line).

[0071] As described above, light stimulation received by the cone cells of the retina is then converted into electrical signals suitable for transmission to the brain (phototransduction) via two main types of neurons: magnocellular neurons or neurons of the magnocellular pathway, and parvocellular neurons or neurons of the parvocellular pathway.

[0072] These pathways mediate human vision by receiving electrical signals from cones and providing information based on the differential absorption of photons by these cones. The magnocellular pathway processes visual stimuli that are fast moving, viewed for a short time, blurry, and / or very faint, while the parvocellular pathway provides color vision and high spatial resolution.

[0073] More precisely, neurons in the magnocellular pathway add the input they receive from M-type cones to the input they receive from L-type cones (M+L). Neurons in the parvocellular pathway subtract the input they receive from L-type cones from the input they receive from M-type cones, and conversely, subtract the input they receive from M-type cones from the input they receive from L-type cones (M-L and L-M).

[0074] Therefore, the bandpass filter 12 of the lens 1 allows to improve the magnocellular / parvocellular stimulation ratio (MPR), i.e. to facilitate the processing of visual stimuli through the magnocellular pathway. The MPR can be estimated as:

[0075]

[0076] Where M is the activity level induced by light stimulation in M-type cones (i.e., the input received from M-type cones), and L is the activity level induced by light stimulation in L-type cones (i.e., the input received from L-type cones).

[0077] It should be noted that various techniques can be employed to measure the level of activity evoked by light stimulation in M- and L-type cones in order to calculate the MPR.

[0078] In some cases, it may be desirable to increase the MPR; for example, when the magnocellular pathway is inactivated and / or the parvocellular pathway is overactive; for example, sleep-deprived subjects, subjects with reading, spelling or writing difficulties, subjects with dyslexia or alexia, or subjects with learning or memory difficulties.

[0079] Increasing the MPR may also be beneficial when rapid responses to moving or changing visual stimuli are required, such as during driving or video gaming, or when viewing moving objects.

[0080] Information from magnocellular and parvocellular neurons is received and processed by the ventral stream and dorsal stream. The former receives information from both types of neurons, while the latter mainly receives information from magnocellular neurons.

[0081] Thus, by increasing the MPR, the bandpass filter 12 also allows the functionality of supporting the dorsal flow, in particular:

[0082] - Visual perception for visually guided behaviors such as catching a ball in flight; driving,

[0083] - handling of motion,

[0084] -Processing of the spatial characteristics (position, orientation) of objects.

[0085] The transmittance of the bandpass filter 12 at the central wavelength is preferably equal to or lower than 20%.

[0086] Figure 3 is a graph showing an exemplary transmittance spectrum of a bandpass filter 12 consistent with the present disclosure. In this example, the transmittance at the center wavelength is equal to 10%.

[0087] Furthermore, the total transmittance of the bandpass filter 12 is preferably equal to or lower than 10%. Preferably, the total transmittance is lower than 4%.

[0088] Such a low total transmittance allows effectively reducing the brightness contrast between the scene (eg, letters or numbers) and the background.

[0089] Blur filter

[0090] The blur filter 13 is configured to attenuate spatial frequencies greater than 10 cycles / degree corresponding to the visual stimulus of the scene. "Attenuation" means that the intensity of the component of the spatial frequency f is reduced by at least 5%, preferably at least 10%, and ideally at least 50%. The component of the spatial frequency f is usually the value obtained by the Fourier transform of the visual stimulus. The cut-off frequency of the blur filter 13 is the lowest spatial frequency for which the attenuation of the spatial frequency is higher than 5%. In other words, the blur filter 13 is a low-pass filter.

[0091] In an embodiment, the blur filter 13 is configured to attenuate spatial frequencies corresponding to the visual stimulus of the scene that are greater than 8 cycles / degree, preferably greater than 6 cycles / degree, and more preferably greater than 4 cycles / degree. Since the edges of the scene correspond to high spatial frequency components of the visual stimulus, the cutoff frequency of the blur filter 13 determines the amount of signal that will stimulate the small cell pathway: the lower the cutoff frequency, the lower the signal available to the small cell pathway.

[0092] The blur filter 13 can be a diffuse filter or a moire filter. For example, a subject looking at the grid through a diffuse filter cannot accurately perceive the boundaries of each line of the grid: it corresponds to a blur filter 13 with a high cutoff frequency. Alternatively, a moire layer - while not diffuse, i.e. purely refractive - can distort the visual stimulus so that adjacent lines appear superimposed without changing the clear perception of the edges: it corresponds to a spatial bandpass filter. The blur filter 13 can be any combination of these two structures - diffuse filter and moire filter.

[0093] This blurring filter 13 is placed in the path of the light beam, interposed between the visual stimulus and the subject's eye, allowing the light beam passing through the lens 1 to be dispersed - by diffusion and / or refraction.

[0094] The blur filter 13 may be a layer or film attached to one side 10, 11 of the lens 1, preferably to the second side 11 ( Figure 1 ).

[0095] For example, the blur filter 13 may be made of a solid diffuse material (eg, a polystyrene sheet), or a solid material having a surface roughness (eg, rough quartz or polytetrafluoroethylene).

[0096] Preferably, the blur filter 13 is detachable, ie it is reversibly attached to the lens 1. Having a detachable blur filter 13 allows obtaining a universal lens 1 that can provide different diffusion capabilities. In this case, the blur filter 13 can be selected and changed depending on the task to be performed by the subject.

[0097] The blur filter 13 allows attenuation of high spatial frequencies of the light stimulus comprising information on fine details of the visual stimulus.

[0098] As a result, the blur filter 13 allows softening the edges of objects viewed therethrough (corresponding to high spatial frequencies), while retaining coarser features (corresponding to lower spatial frequencies).

[0099] In general, the blur filter 13 allows to modify the visual perception of the subject of a visual stimulus by providing a blurring effect to the light stimulus reaching the eye 2. Examples of blurring effects are shown in Figure 4 Shown in.

[0100] More precisely, Figure 4 is not used ( Figure 4 A) and use ( Figure 4 B) Schematic diagram of text observed by the optical lens 1 including the bandpass filter 12 and the blur filter 13.

[0101] Advantageously, the blur filter 13 allows further facilitating the processing of visual information in the magnocellular pathway rather than the parvocellular pathway, since the former processes blurry, faint stimuli, while the latter processes sharp-edged, high-contrast stimuli. Thus, an improved MPR is obtained.

[0102] Thus, due to the combination of the wavelength filtering properties provided by the bandpass filter 12 and the blurring effect provided by the blurring filter 13, the optical lens 1 comprising both the bandpass filter 12 and the blurring filter 13 allows for significant upregulation of the magnocellular pathway and improved visual perception.

[0103] When the blur filter 13 comprises a diffusion filter, its characteristics may be as follows: if the light from two adjacent peaks is superimposed by diffusion, the component of the spatial frequency f of the visual stimulus will be attenuated. For example, if the light from one peak is scattered over a sufficiently large angle, two peaks (corresponding to a spatial frequency f=10) separated by 0.1° in the visual stimulus will be superimposed. Assuming that the distance between the lens and the eye is 1 cm, the scattering angle should be greater than 5°. Therefore, the blur filter 13 can be used with a normal incident angle (i.e., light perpendicular to the surface of the blur filter 13, see Figure 1 ), which is the percentage of light transmitted by the blur filter 13 outside a predefined dispersion angle β. Therefore, the diffusion power is expressed as %:β.

[0104] For example, in a completely non-diffusing material, all incident light (i.e. 100%) is transmitted through the material without changing its direction (i.e. no scattering). In this case, the diffusing power is 0%: 0°.

[0105] The blur filter 13 may have a diffusion capability equal to or less than 20%:16°, ie, the blur filter 13 transmits 20% or less of incident light outside a dispersion angle β of 16° (which corresponds to transmitting more than 80% of light within the angle β).

[0106] In some examples, the diffusion power of blur filter 13 is equal to or less than 20%:10°.

[0107] Preferably, the diffusion capability of the blur filter 13 is greater than 5%:3°, more preferably greater than 10%:5°.

[0108] The lower the diffusion power, the less blurring effect the blur filter provides.

[0109] Advantageously, the diffusing power comprised between 20%:16° and 10%:5° is high enough to provide blurring of light stimuli and small enough to ensure that the visual stimuli are correctly perceived by the subject (e.g., for visual stimuli present in text, the diffusing power is small enough to ensure that the blurred letters and numbers are recognized by the subject and can be read by the subject).

[0110] In a preferred embodiment, blur filter 13 is a frost filter, such as the diffusion filter provided by LEE Filters (Panavision).

[0111] When the blur filter 13 comprises a corrugation filter, the same reasoning applies except that the angle α to be considered is not a scattering angle, but a refraction angle γ. Thus, the blur filter 13 can be defined by the refractive power at normal incidence (i.e., light perpendicular to the surface of the blur filter 13), which is the percentage of light transmitted by the blur filter 13 with a deviation angle equal to or greater than γ. The refractive power is thus expressed as %:γ.

[0112] For example, in a perfectly flat lens, all incident light (i.e. 100%) transmits through the material without changing its direction (i.e. not being refracted). In this case, the refractive power is 0%: 0°.

[0113] The blur filter 13 may have a refractive power equal to or less than 20%:16°, that is, the blur filter 13 refracts 20% or more of incident light having a refraction angle γ of 16° or more (which corresponds to less than 80% of light having a low refraction angle being transmitted).

[0114] In some examples, the refractive power of the blur filter 13 is equal to or less than 20%:10°. Preferably, the refractive power of the blur filter 13 is greater than 5%:3°, more preferably greater than 10%:5°.

[0115] Since both the diffusion power and the refractive power are expressed in the same form and both define the amount of light that is deviated, the blur filter can be characterized by the deviating power, which is the sum of the diffusion power and the refractive power. The blur filter 13 can have a deviating power equal to or less than 20%: 16°, that is, the blur filter 13 refracts 20% or more of the incident light with a deviating angle γ of 16° or more (which corresponds to less than 80% of the light being transmitted with low refraction or low diffusion).

[0116] In some examples, the deviation capability of the blur filter 13 is equal to or less than 20%:10°. Preferably, the deviation capability of the blur filter 13 is greater than 5%:3°, more preferably greater than 10%:5°.

[0117] The combination of the bandpass filter and the blur filter advantageously reduces contrast and high spatial frequencies of a scene viewed through the optical lens and suppresses parvocellular flow in a subject wearing the optical lens.

[0118] Ophthalmic lenses and glasses

[0119] The invention also relates to a pair of spectacles comprising a frame and a pair of optical lenses 1 as described above.

[0120] For example, the bandpass filter 12 and blur filter 13 may be cut and shaped from films or layers to fit the substrate of the optical lens 1 of the spectacles.

[0121] In this case, the thickness of the bandpass filter 12 and the blur filter 13 is preferably about 0.1 mm or less.

[0122] Material

[0123] The optical lens 1 may be made of any material suitable for placement facing the eye 2 of a subject (eg, glass or plastic).

[0124] As mentioned above, the optical lens 1 may have a layered structure, for example, a three-layer structure including a substrate 14 , a bandpass filter 12 and a blur filter 13 .

[0125] In this case, the substrate 14, the bandpass filter 12 and the blur filter 13 can be laid out so that the light stimulus passes through before reaching the eye 2:

[0126] - a bandpass filter 12, then through a substrate 14, then through a blur filter 13;

[0127] - blur filter 13, then through substrate 14, then through bandpass filter 12;

[0128] - a bandpass filter 12, then through a blur filter 13, then through a substrate 14;

[0129] - blur filter 13, then through bandpass filter 12, then through substrate 14;

[0130] - substrate 14, then through blur filter 13, then through bandpass filter 12; or

[0131] - substrate 14, then passes through the bandpass filter 12 and then through the blur filter 13.

[0132] Preferably, in the case where the optical lens 1 has a three-layer structure, the substrate 14 is located in the middle, the blur filter 13 is laid on the second side 11, and the bandpass filter 12 is laid on the first side 10, such as Figure 1 Schematically shown in .

[0133] In some examples, the optical lens may have a one-layer or two-layer structure.

[0134] For example, the substrate 14 of the optical lens 1 may be a colored lens doped with an appropriate dye and having the wavelength filtering characteristics of the aforementioned bandpass filter 12 .

[0135] In this case, the function of the bandpass filter 12 is provided by the substrate material 14 .

[0136] Furthermore, the substrate 14 of the optical lens 1 may have a rough surface (preferably, disposed on the second side 11 ).

[0137] In this case, the function of the blur filter 13 is provided by the substrate material 14, more precisely by the rough surface.

[0138] Method for selecting the optimal lens

[0139] The invention also relates to a method for selecting an optical lens 1 for improving the visual perception of a subject.

[0140] The method may comprise a first measuring step in which one or more optical parameters of the subject are measured.

[0141] Then, at least one optical lens 1 is provided to the subject, and the subject places the optical lens 1 at a predetermined distance from the scene and the eye (for example, 60 cm from the scene and 1 cm from the eye).

[0142] In the measuring step, optical parameters of the subject are measured while the subject wears the optical lens 1 .

[0143] Preferably, the measuring step may include several stages. During the first stage, different optical lenses 1 are sequentially provided to the subject. The bandpass filters 12 of these optical lenses 1 have different characteristics. The measurement of the optical parameters is repeated for each optical lens 1, and then the optical lens 1 corresponding to the best optical parameter among the plurality of optical lenses 1 is selected. The characteristics of the bandpass filter 12 can be selected from the following list: central wavelength, FWHW, maximum transmittance, total transmittance, or a combination thereof.

[0144] During the second stage, different blur filters 13 with different characteristics are sequentially coupled to the selected optical lens 1. When each blur filter 13 is arranged on the selected lens 1, the measurement of the optical parameters is repeated, and then the blur filter 13 corresponding to the best optical parameters is selected. The characteristics of the blur filter 13 can be selected from the following list: cut-off frequency, attenuation level, shape of the cut-off (first order, second order or higher order), or a combination thereof.

[0145] In the method, at least two optical lenses 1 having different filtering characteristics of the bandpass filter 12 and / or different characteristics of the blur filter 13 are provided to the subject and the optical parameters of the subject are measured to select the optical lens corresponding to the best measured optical parameters. Preferably, the measurement settings - scene type, eye / lens and scene / lens distances, illumination - remain constant for all optical lenses 1 tested.

[0146] The method described above advantageously allows identification of an optimal optical lens 1 for improving the visual perception of a subject having a typical visual system.

[0147] Preferably, the optical parameter is a perception threshold for a subject having a typical visual system.

[0148] For example, the subject's visual motion direction perception threshold can be measured during the first estimation step. Such a measurement can be performed, for example, by means of a four-forced-choice random-point motion map and an adaptive staircase procedure.

[0149] Furthermore, the subject's visual motion speed perception threshold can be measured during the first measuring step. This can be performed, for example, by a motion speed discrimination task and an adaptive staircase procedure.

[0150] The method described above also allows identifying an optimal optical lens 1 for improving the visual perception of a subject with a disorder of the magnocellular visual pathway, preferably a subject with dyslexia.

[0151] In this case, the optical parameter is preferably a parameter related to reading efficiency, such as an inverse efficiency index.

[0152] This optical parameter can be measured by any known reading test (e.g., by providing a list of pseudo-words consisting of direction-sensitive letters that the subject must read aloud). The inverse efficiency index can be calculated by dividing the reading time by the percentage of error.

[0153] The reading test may comprise a linear arrangement of symbols, numbers and / or letters. Preferably, the reading test comprises pseudo-words. Tests comprising pseudo-words are particularly suitable for assessing the reading efficiency of people with dyslexia.

[0154] Methods for improving visual perception

[0155] The invention also relates to a method for improving visual perception.

[0156] In particular, the method allows to improve the perception of moving or transient visual stimuli.

[0157] The method comprises inserting the optical lens 1 disclosed above (or spectacles comprising the optical lens 1 ) between the subject's eye 2 and a visual stimulus.

[0158] In an embodiment, the optical lens 1 comprises a bandpass filter 12 , the central wavelength of the bandpass filter is 540 nm to 560 nm, and the full width at half maximum is equal to or lower than 50 nm.

[0159] In another embodiment, the optical lens 1 comprises a blur filter (13) configured to attenuate spatial frequencies greater than 10 cycles / degree corresponding to the visual stimulus of the scene.

[0160] In another embodiment, the optical lens 1 comprises

[0161] • a bandpass filter 12 having a central wavelength of 540 nm to 560 nm and a full width at half maximum equal to or lower than 50 nm; and

[0162] • A blur filter (13) configured to attenuate spatial frequencies greater than 10 cycles / degree corresponding to the visual stimulus of the scene.

[0163] For example, the visual stimulus can be a moving object or a transient stimulus observed by a stationary or moving subject.

[0164] The insertion lens 1 facilitates the processing of light stimuli through the magnocellular pathway, ie due to the combination of the bandpass filter 12 and the blur filter 13 the MPR is increased.

[0165] Methods for treating disorders

[0166] Finally, the present invention also relates to a method for treating a disorder of the magnocellular and / or parvocellular visual pathways of a subject. The method comprises inserting the optical lens or glasses disclosed above between the subject's eye and the scene. The magnocellular flow will then be more requested, resulting in an eventual reduction in the disorder.

[0167] In an embodiment, the optical lens 1 comprises a bandpass filter 12 , the central wavelength of the bandpass filter is 540 nm to 560 nm, and the full width at half maximum is equal to or lower than 50 nm.

[0168] In another embodiment, the optical lens 1 comprises a blur filter (13) configured to attenuate spatial frequencies greater than 10 cycles / degree corresponding to the visual stimulus of the scene.

[0169] In another embodiment, the optical lens 1 comprises

[0170] • a bandpass filter 12 having a central wavelength of 540 nm to 560 nm and a full width at half maximum equal to or lower than 50 nm; and

[0171] • A blur filter (13) configured to attenuate spatial frequencies greater than 10 cycles / degree corresponding to the visual stimulus of the scene.

[0172] Preferably, the method is used in a subject suffering from dyslexia.

[0173] Example

[0174] The present invention is further illustrated by the following examples.

[0175] Example 1: Reading Test

[0176] In this experiment, participants with dyslexia who had severe difficulty reading pseudowords consisting of directionally sensitive letters (e.g., p, b, d, q) were exposed to a list of pseudowords (e.g., "padaba") that included directionally sensitive letters and were asked to read as many pseudowords as possible in 1 min. The number of pseudowords that the subjects read accurately in one minute was counted. Reading efficiency was calculated as the total number of words read accurately.

[0177] The experiment was repeated when the subject was not wearing any lens, and when the subject was wearing a different lens including a bandpass filter with a center wavelength and a FWHM of 50 nm. The difference between these optical lenses is that each optical lens includes a bandpass filter with a different center wavelength. The center wavelengths tested were: 440 nm, 445 nm, 450 nm, 500 nm, 520 nm, 550 nm, 570 nm, 600 nm, 630 nm, 650 nm, 670 nm.

[0178] The results obtained are Figure 5 More precisely, Figure 5 is a graph showing the reading efficiency per minute (vertical axis) as a function of the central wavelength of the bandpass filter (horizontal axis) for a person with severe dyslexia without any filter and with 11 different filters of different properties. The numbers on the axis refer to the central wavelength of the bandpass filter (in nm). The leftmost category on the horizontal axis (labeled "None") corresponds to the subject reading without using any lenses.

[0179] These results show that the best reading efficiency is obtained using an optical lens 1 comprising a bandpass filter 12 having a central wavelength equal to 550 nm.

[0180] Adding a blur filter (2016 White diffusion from LEE Filters) allowed the subjects to improve their reading ability.

[0181] Example 2: Stroke letters

[0182] In this experiment, participants with dyslexia had to find and cross out as many words as possible in 30 seconds. Figure 6 The letter "d" is shown hidden among other letters on a page - a list. The other letters are either mirror images (b, q), phonologically close letters (g), or other letters. Each list includes the target letter "d" 48 times, the mirror image "b" 24 times, the mirror image "q" 24 times, 24 other "overline" letters (f, h, k, l, t), 24 "underline" letters (j, g, y), 24 vowels, 24 letters phonologically close to "d" (m, n), and 72 other letters (w, x, c, s, r, v, z), in random order. The letters are printed in black ink in Calibri size 13, arranged in 6 rows with a space between letters, on white A4 paper. During testing, the white sheet is backlit by a projector to a luminance of approximately 100 cd / m 2 .

[0183] The test was repeated 40 times (organizing the order of the letters in different ways): 20 times the participant wore an optical lens comprising a bandpass filter with a central wavelength of 50 nm and a central wavelength of 550 nm - Filter - and 20 times the participant wore another filter with different spectral characteristics that reduced the contrast to the same extent as the filter - Reference A. For each repetition of the exercise, the participant received a score equal to the difference between the number of crossed-out "d"s and the number of other letters crossed out (i.e., the number of errors). If the filter effect is medium (Cohen's test, d value of 0.5), 20 repetitions provide appropriate statistical power (75%) to observe a statistically significant effect of the filter (Student's t test for paired samples), and if the filter effect is large, 20 repetitions provide very high statistical power (96%) to observe a statistically significant effect of the filter (Cohen's test, d value of 0.8). Since the filter and reference A conditions were presented in a mixed order, the effect of the filter was not confounded with the effect of the order.

[0184] The second test was performed with 40 repetitions, using the same filter and another contrast-reducing filter - Reference B. The contrast reduction was identical for Reference A and Reference B, but was achieved in different ways.

[0185] When a participant wore the filter, his or her performance on the letter-scratching test improved.

[0186] Adding a blur filter (2016 White Diffuse from LEE Filters) allowed the subjects to improve their letter-scribing performance.

[0187] Example 3: Lexical Decision

[0188] In this experiment, participants were presented with either a real word (e.g., “baleine” – whale in English) or a non-real word (pseudo-word) that was constructed by converting the letters of the real word into “mirror” letters (e.g., “daleine”) or phonologically similar letters (e.g., “galeine”). Participants had to decide as quickly as possible (by pressing a button) whether the sequence of letters displayed on the screen was a real word or a non-real word. The letters were displayed in black ink, Calibri size 10, in the center of the screen against a white background. The experiment included a total of 100 real words, 100 pseudo-words composed of mirrored letters, and 100 pseudo-words composed of phonologically similar letters. The stimuli were divided into 4 groups (1, 2, 3, and 4), each with 25 words, 25 “mirror” pseudo-words, and 25 “phonological” pseudo-words. All stimuli were presented to participants wearing optical lenses that included a bandpass filter with a central wavelength of 550 nm with a FWHM of 50 nm (A)—filters, and to participants not wearing optical lenses (B)—in the following order: A1, B2, A3, B4, B1, A2, B3, A4, so that possible effects of the filters were not confounded with effects of order. For each participant, mean reaction times in the filtered and unfiltered conditions were compared in an ANOVA with order as a covariate.

[0189] A second field test is performed using the same filter and another filter that reduces the contrast to the same order as the filter - the reference. The contrast reduction is the same for both the filter and the reference, but is achieved in different ways.

[0190] When a participant wore the filter, his / her performance on the lexical decision test improved.

[0191] Adding a blur filter (2016 White Diffuse from LEE Filters) allowed subjects to improve their lexical decision performance.

[0192] Example 4: Cognitive Effort

[0193] In this experiment, participants performed different reading tasks (reading words, sentences) while wearing an optical lens including a bandpass filter with a central wavelength of 50 nm FWHM and a central wavelength of 550 nm - the filter - and without wearing the optical lens. During the test, the pupil diameter of the participants was measured using an eye tracker (EyeLink 1000 from SR Research LLC). Pupil dilation is correlated with cognitive effort.

[0194] When a participant wore the filter, his / her cognitive effort during reading decreased.

[0195] Adding a blur filter (2016 White Diffuse from LEE Filters) allowed the subjects to reduce their cognitive effort while reading.

Claims

1. An optical lens (1) for enhanced visual perception of a scene, the optical lens having a first side (10) configured to face an eye (2) of a subject, and a second side (11) opposite the first side (10), the optical lens (1) comprising: • a bandpass filter (12) having a central wavelength of 540 nm to 560 nm and a full width at half maximum equal to or less than 50 nm; and • A blur filter (13) configured to attenuate spatial frequencies greater than 10 cycles / degree corresponding to the visual stimulus of the scene.

2. The optical lens (1) according to claim 1, wherein the central wavelength of the bandpass filter (12) is 545 nm to 555 nm, preferably equal to 550 nm.

3. The optical lens (1) according to any one of claims 1 to 2, wherein the total transmittance of the bandpass filter (12) is equal to or lower than 10%, preferably lower than 4%.

4. The optical lens (1) according to any one of claims 1 to 3, wherein the blur filter (13) is configured to attenuate spatial frequencies corresponding to the visual stimulus of the scene greater than 8 cycles / degree, preferably greater than 6 cycles / degree, more preferably greater than 4 cycles / degree.

5. The optical lens (1) according to any one of claims 1 to 4, wherein the bandpass filter (12) is laid on a first side (10) of the optical lens (1), and the blur filter (13) is laid on a second side (11) of the optical lens (1).

6. The optical lens according to any one of claims 1 to 5, wherein the blur filter (13) is made of a solid diffuse material or a solid material with surface roughness, preferably rough quartz or polytetrafluoroethylene.

7. The optical lens (1) according to any one of claims 1 to 6, wherein the optical lens (1) is an ophthalmic lens, preferably a spectacle lens.

8. Spectacles comprising a frame and a pair of spectacles lenses according to claim 7.

9. A method for selecting an optical lens to enhance a subject's visual perception of a scene, the method comprising: a. providing a subject with an optical lens (1) according to any one of claims 1 to 7 or a pair of glasses according to claim 8, wherein the optical lens (1) or the pair of glasses is inserted between the subject's eye (2) and a scene at a predetermined distance from the subject's eye (2) and the scene; b. measuring the optical parameters of the subject, wherein the providing and measuring are repeated for at least two optical lenses or glasses having the bandpass filters (12) with different filtering characteristics and / or the blur filters (13) with different characteristics; and c. Select, from among the provided optical lenses (1) or glasses, the optical lens (1) or glasses corresponding to the measured optimal optical parameters.

10. The method according to claim 9, wherein the optical parameter is selected from the following list: reading efficiency, inverse efficiency index, visual motion direction perception threshold, visual motion speed perception threshold.

11. The method according to claim 9 or 10, wherein the scene comprises a linear arrangement of symbols, numbers and / or letters.

12. A method for improving the visual perception of a subject by inserting an optical lens (1) according to any one of claims 1 to 7 or a pair of glasses according to claim 8 between the subject's eye (2) and a visual stimulus.

13. A method for treating damage to the magnocellular and / or parvocellular visual pathways of a subject, the method comprising inserting an optical lens (1) according to any one of claims 1 to 7 or a pair of spectacles according to claim 8 between the subject's eye (2) and a scene.

14. The method of claim 13, wherein the subject is a subject with dyslexia.

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