Optical system

Abstract

An optical system intended to be worn in front of the eyes of a wearer, the optical system comprising:-an optical lens having at least a control point, and-an optical device comprising a plurality of optical elements, the optical device being attached on a surface of the optical lens or encapsulated in the optical lens, -each optical element simultaneously has two different optical functions, and-the optical device and the optical lens are configured such that the absolute value of the difference between the focal power measured at the control point of the optical system and the focal power corresponding to the prescription of the eye of the person is less than or equal to 0.12 diopter.

Description

[0001] This application is a divisional application of the invention patent application entitled “Optical System”, which has Chinese application number 202080048104.3 and filing date July 3, 2020, PCT application PCT / EP2020 / 068783. Technical Field

[0002] The present invention relates to an optical system intended to be worn in front of a person's eyes to inhibit the development of eye refractive errors (such as myopia or hyperopia), and an optical device intended to be placed on the surface of an optical lens or inside an optical lens in order to add optical power to the optical lens. Background Art

[0003] Myopia of the eye is characterized by the eye focusing distant objects in front of its retina, and hyperopia is characterized by the eye focusing distant objects behind its retina. Myopia is usually corrected using concave lenses, and hyperopia is usually corrected using convex lenses.

[0004] It has been observed that some individuals, especially children, focus images inaccurately when corrected with conventional single vision optical lenses for two main reasons. When they observe distant objects, even if the image is focused on the central retina, the peripheral image may be focused behind the retina due to the retinal curvature. Also, with the same lens, when they observe objects at a closer distance, the image may also be formed behind his retina (even in the fovea area) due to the lag of accommodation.

[0005] This focusing defect may have an impact on the progression of myopia in such individuals. It can be observed that for most of these individuals, the myopia defect tends to worsen over time.

[0006] Therefore, there seems to be a need for a lens element that is able to inhibit or at least slow down the progression of refractive errors of the eye, such as myopia or hyperopia. Summary of the invention

[0007] To this end, the present invention proposes an optical system intended to be worn in front of the wearer's eyes, the optical system comprising:

[0008] - an optical lens having at least one control point, and

[0009] - an optical device comprising a plurality of optical elements, the optical device being attached to the surface of the optical lens or being encapsulated in the optical lens,

[0010] in,

[0011] - Each optical element has two different optical functions simultaneously, and

[0012] - The optical device and the optical lens are configured so that the absolute value of the difference between the optical focal length measured at a certain point of the optical system, such as a control point, and the optical focal length corresponding to the prescription of the eye of the person is less than or equal to 0.12 diopters.

[0013] Advantageously, an optical device comprising multiple optical elements that simultaneously provide two different optical functions allows for an easily configurable optical system that, when worn by the wearer, reduces the progression of refractive errors of the eye (such as myopia or hyperopia) by focusing part of the light on the wearer's retina for central vision and part of the light in front of or behind the wearer's retina for peripheral vision.

[0014] According to further embodiments which may be considered alone or in combination:

[0015] - the optical device is configured so that, for at least one optical element, the absolute value of the difference between at least one optical power measured through the optical element of the optical system and the optical power measured only through the corresponding part of the optical lens is less than or equal to 0.25 diopters; and / or

[0016] - the first optical function has a mean optical power less than or equal to 0.25 diopters and may be, for example, a spherical or sphero-toric optical function; and / or

[0017] - the second optical function of at least some of the optical elements has an average optical power greater than or equal to 0.5 diopters; and / or

[0018] - a second optical function of at least a portion of the optical elements is such that when the optical system is worn under standard wearing conditions, an image is not focused on the retina of the eye, so as to slow down the development of refractive errors in the eye; and / or

[0019] - the second optical function of at least a portion of said optical elements is an aspherical optical function; and / or

[0020] - a first optical function of at least a portion of said optical elements is such as to focus an image on the retina of said eye when said optical system is worn under standard wearing conditions for at least said central vision; and / or

[0021] - the optical device is attached to the front surface of the optical lens or to the back surface of the optical lens or to a surface comprised between the front surface and the back surface of the optical lens; and / or

[0022] - at least a portion of said optical element is continuous; and / or

[0023] - all of said optical elements are continuous; and / or

[0024] - at least a portion, for example all, of said optical elements are arranged along a plurality of concentric rings; and / or

[0025] - at least a portion, for example all, of said optical elements are made of a birefringent material; and / or

[0026] - at least some, for example all, of the optical elements are diffractive lenses; and / or

[0027] - the diffractive lens comprises two main diffraction orders, a first main diffraction order providing a first average optical power with an absolute value less than or equal to 0.25 diopters, and a second main diffraction order providing a second average optical power greater than or equal to 0.5 diopters; and / or

[0028] - at least some, for example all, of said optical elements are π-Fresnel lenses; and / or

[0029] - at least a portion, for example all, of said diffractive lenses comprise a Metasurface structure; and / or

[0030] - at least some, for example all, of the optical elements are multifocal binary components; and / or

[0031] - at least some, for example all, of said optical elements are pixelated lenses; and / or

[0032] - the optical system has regions without optical elements, for example said regions comprising control points; and / or

[0033] - the optical elements have a square or hexagonal outline and are arranged according to a predefined array, for example a square or hexagonal array; and / or

[0034] - at least a portion, for example all, of the optical elements are arranged so that every point of their contours touches another optical element; and / or

[0035] - at least a portion, for example all, of said optical elements are arranged according to a predefined array, for example a square or hexagonal array; and / or

[0036] - the optical system comprises a prescription part configured to provide a corrective optical function to the wearer under standard wearing conditions based on the wearer's prescription for correcting ametropia of the eye of the wearer; and / or

[0037] - the optical lens is an edged optical lens intended to be mounted in a spectacle frame and the entire surface of at least one face of the optical lens is covered with the plurality of optical elements; and / or

[0038] - the optical lens is an edged optical lens intended to be mounted in a spectacle frame and the entire aperture of the optical lens is covered with the plurality of optical elements; and / or

[0039] - the difference between the optical power of the corrective optical function and the average optical power of the second optical function is greater than or equal to 0.5D; and / or

[0040] - each optical element has an optical axis; and / or

[0041] - at least one, for example all, of said optical elements are shaped so as to form a focal point in front of the retina of said person's eye; and / or

[0042] - At least some, for example all, of said optical elements have an optical function comprising higher order optical aberrations.

[0043] The disclosure further relates to an optical device intended to be placed on the surface of an optical lens in order to add an optical function to said optical lens and, for example, to form an optical system according to the invention, said optical device comprising a plurality of optical elements, wherein each optical element simultaneously has two different optical functions, while providing:

[0044] - a first mean optical power having an absolute value less than or equal to 0.25 diopters, and

[0045] - a second mean optical power greater than or equal to 0.5 diopters.

[0046] According to further embodiments which may be considered alone or in combination:

[0047] - at least a portion of said optical element is continuous; and / or

[0048] - all of said optical elements are continuous; and / or

[0049] - at least a portion, for example all, of said optical elements are arranged along a plurality of concentric rings; and / or

[0050] - at least a portion, for example all, of said optical elements are made of a birefringent material; and / or

[0051] - at least some, for example all, of the optical elements are diffractive lenses; and / or

[0052] - the diffractive lens comprises two main diffraction orders, a first main diffraction order providing a first average optical power with an absolute value less than or equal to 0.25 diopters, and a second main diffraction order providing a second average optical power greater than or equal to 0.5 diopters; and / or

[0053] - the second optical function of at least a portion of said optical elements is an aspherical optical function; and / or

[0054] - at least some, for example all, of said optical elements are π-Fresnel lenses; and / or

[0055] - at least a portion, for example all, of said diffractive lenses comprise a Metasurface structure; and / or

[0056] - at least some, for example all, of the optical elements are multifocal binary components; and / or

[0057] - at least some, for example all, of said optical elements are pixelated lenses; and / or

[0058] - the optical device has areas without optical elements; and / or

[0059] - at least a part, e.g. all, of said optical elements have a square or hexagonal outline and are arranged according to a predefined array, e.g. a square or hexagonal array, e.g. provided on at least one surface of said lens element; and / or

[0060] - at least a portion, for example all, of said optical elements are arranged according to a predefined array, for example a square or hexagonal array, to cover the full aperture of said lens element; and / or

[0061] - at least a part, for example all, of said optical elements are arranged according to a predefined array, said optical elements being completely continuous,

[0062] - the optical device is rigid or flexible; and / or

[0063] - the optical device is one of a film, a patch or a wafer; and / or

[0064] - the average radius of curvature of the optical device is between 88 mm and 53 mm, preferably equal to 66 mm; and / or

[0065] - the optical device has an average thickness between 5 mm and 0.5 mm, measured perpendicularly to at least one face of the device; and / or

[0066] - the optical device comprises a transparent material having a Shore A hardness between 70 and 95; and / or

[0067] - the optical device comprises a transparent material with a light scattering percentage between 2.0% and 0.4%, preferably less than 1%; and / or

[0068] - the optical device comprises a transparent thermoplastic material selected from the polymers polyurethane, polyvinyl chloride, polyethylene terephthalate, poly(methyl methacrylate) and polycarbonate; and / or

[0069] - the optical device comprises a transparent material selected from polyurethane thermoplastics and polyvinyl chloride thermoplastics; and / or

[0070] - each optical element has an optical axis; and / or

[0071] - at least one, for example all, of said optical elements are shaped so as to form a focal point in front of the retina of said person's eye; and / or

[0072] - At least some, for example all, of said optical elements have an optical function comprising higher order optical aberrations.

[0073] The present disclosure also relates to a method for providing an optical system intended to be worn in front of an eye of a wearer, wherein the method comprises the following steps:

[0074] - providing an optical lens configured to provide a corrective optical power to the wearer under standard wearing conditions based on the wearer's prescription for correcting ametropia of the eye of the wearer,

[0075] - providing an optical device according to the present disclosure,

[0076] - forming an optical system by placing the optical device on one surface of the optical lens or by encapsulating the optical device into the optical lens.

[0077] The present disclosure further relates to a method for providing an optical system intended to be worn in front of a wearer's eye, wherein the method comprises the following steps: forming an optical system by packaging an optical device according to the present disclosure into an optical lens configured to provide corrective optical power to the wearer under standard wearing conditions based on the wearer's prescription for correcting the refractive error of the wearer's eye, and placing the optical device on one surface of the optical lens.

[0078] The present disclosure also relates to a method for providing an optical system intended to be worn in front of an eye of a wearer, wherein the method comprises the following steps:

[0079] - providing a semi-finished optical lens incorporating an optical device according to the present disclosure,

[0080] - determining the back surface to be machined on said semi-finished optical element to match said wearer's prescription,

[0081] - machining the rear surface of the provided semi-finished optical lens to obtain a defined rear surface.

[0082] The invention further relates to a method for providing an optical system intended to be worn in front of an eye of a wearer, wherein the method comprises a step of casting the optical system and providing an optical device according to the present disclosure during the casting step. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Non-limiting embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0084] Figure 1a is a general outline view of an optical system according to the present invention;

[0085] Figure 1b is a plan view of an optical system according to the present invention;

[0086] Figure 2 represents an example of an optical system covered by a plurality of continuous Fresnel-type optical elements;

[0087] Figure 3 An example showing the radial profile of the first diffractive lens;

[0088] Figure 4 An example showing the radial profile of the second diffractive lens;

[0089] Figure 5 The radial profile of the π-Fresnel lens is shown;

[0090] Figure 6a and Figure 6b shows that the diffraction efficiency of a π-Fresnel lens profile varies with wavelength, and

[0091] Figures 7a to 7c A binary lens embodiment of the present invention is shown.

[0092] The elements in the drawings are shown only for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve understanding of the embodiments of the present invention. DETAILED DESCRIPTION

[0093] The invention relates to an optical system, in particular an optical system intended to be worn in front of a person's eyes, and an optical device.

[0094] In the rest of this specification, terms such as "upper", "bottom", "horizontal", "vertical", "above", "below", "front", "back", etc., or other words indicating relative positions may be used. These terms should be understood in the wearing conditions of the optical system.

[0095] In the context of the present invention, the term "optical lens" may refer to a contact lens, an uncut optical lens or an optical lens that is edged to fit a specific spectacle frame, or an ophthalmic lens.

[0096] In the context of the present invention, the term "optical device" refers to an optical device suitable for being positioned on or inside an optical lens. The optical device may be positioned on the front surface or the back surface of the optical lens or on a surface between the front surface and the back surface of the optical lens, or inserted into the optical lens. The optical device may be an optical patch, a film or a wafer.

[0097] An optical system 10 according to the present disclosure is adapted for a person and is intended to be worn in front of the eyes of the person.

[0098] like Figure 1a As shown, an optical system 10 according to the present disclosure may include:

[0099] - an optical lens 20, and

[0100] - Optical means 30 attached to surface F1 of the optical lens.

[0101] The optical lens 20 includes at least a control point. For example, the control point may be the geometric center of the optical lens or the optical center of the optical lens. If the optical lens 20 is a progressive ophthalmic lens, the control point may be a fitting cross, a far vision reference point, or a near vision reference point.

[0102] exist Figure 1a In the example shown, the optical lens has an object-side surface F1 (eg, formed as a convex surface facing the object side) and an eye-side surface F2 (eg, formed as a concave surface having a curvature different from that of the object-side surface F1).

[0103] According to an embodiment of the present invention, the optical device 30 is located on the front surface of the optical lens 20 .

[0104] Alternatively, the optical device 30 may be located on the rear surface of the optical lens.

[0105] Alternatively, the optical device may be packaged into the optical lens, between the front and back surfaces of the optical lens.

[0106] like Figure 1b As shown, the optical device 20 according to the present invention includes a plurality of optical elements 14 .

[0107] The plurality of optical elements may be arranged such that the optical system 10 includes a prescription portion 12 configured to provide a corrective optical function to the wearer under standard wearing conditions based on the wearer's prescription for correcting ametropia of the wearer's eye.

[0108] The wearing condition is understood as the position of the lens element relative to the wearer's eye, as defined by the anteversion angle, cornea to lens distance, pupil to cornea distance, center of rotation of the eye (CRE) to pupil distance, CRE to lens distance, and wrap angle.

[0109] The cornea-to-lens distance is the distance between the cornea and the posterior surface of the lens along the visual axis of the eye in primary position (usually considered to be horizontal), for example, equal to 12 mm.

[0110] The pupil-to-cornea distance is the distance between the pupil and the cornea of ​​the eye along its visual axis and is usually equal to 2 mm.

[0111] The CRE-to-pupillary distance is the distance along the visual axis of the eye between its center of rotation (CRE) and the cornea, for example, equal to 11.5 mm.

[0112] The CRE-to-lens distance is the distance between the CRE of the eye and the posterior surface of the lens along the visual axis of the eye in the primary eye position (generally considered to be horizontal), for example equal to 25.5 mm.

[0113] The anteversion angle is the angle in the vertical plane between the normal to the back surface of the lens and the visual axis of the eye in the first eye position (usually considered to be horizontal) at the intersection between the back surface of the lens and the visual axis of the eye in the first eye position, for example equal to -8°.

[0114] The wrap angle is the angle in the horizontal plane between the normal to the back surface of the lens and the visual axis of the eye in the first eye position (usually considered to be horizontal) at the intersection between the back surface of the lens and the visual axis of the eye in the first eye position, for example equal to 0°.

[0115] An example of a standard wearer condition may be defined by an anteversion angle of -8°, a cornea-to-lens distance of 12 mm, a pupil-to-cornea distance of 2 mm, a CRE-to-pupil distance of 11.5 mm, a CRE-to-lens distance of 25.5 mm, and a wrap angle of 0°.

[0116] The term "measured optical power" is to be understood as measured with a lens meter.

[0117] The term "prescription" is understood to mean a set of optical characteristics of power, astigmatism, prismatic deviation, axis position, which are determined by an ophthalmologist or optometrist in order to correct the wearer's visual impairment, for example with the aid of a lens positioned in front of the wearer's eye. For example, a prescription for myopia comprises a power value and an astigmatism value with an axis position determined for distance vision.

[0118] Each optical element 14 of the plurality of optical elements simultaneously has two different optical functions and, for example, one optical axis.

[0119] The optical device and the optical lens can be configured so that the absolute value of the difference between one of the optical focal lengths measured at a point in the optical system, such as a control point, and the optical focal length corresponding to the prescription of the eye of the same person is less than or equal to 0.12 diopters, for example less than or equal to 0.05 diopters.

[0120] An optical device according to the present disclosure may be configured such that, for at least one optical element, the absolute value of the difference between at least one optical power measured through the optical element of the optical system and the optical power measured only through the corresponding portion of the optical lens is less than or equal to 0.25 diopters, for example less than or equal to 0.12 diopters.

[0121] The optical function of each optical element 14 may be different from each other.

[0122] The first optical function may be a spherical optical function having an optical power less than or equal to 0.25 diopters, such as less than or equal to 0.12 diopters, or an optical function having an average optical power less than or equal to 0.25 diopters, such as less than or equal to 0.12 diopters.

[0123] Thus, each optical element combined with the optical lens can provide two optical powers under standard wearing conditions. The optical power corresponding to the first optical function provides an optical power close to the prescribed optical power, ie the difference is less than or equal to 0.25 diopters.

[0124] The first optical function of at least a portion of the optical elements may be such that, when the optical system is worn under standard wearing conditions, the image is focused on the central retina of the eye regardless of the direction of eye gaze.

[0125] The second optical function of at least a portion of the optical elements may have an average optical power greater than or equal to 0.5 diopters, for example greater than 1 diopters.

[0126] The second optical function of at least a portion of the optical elements may be to not focus the image on the retina of the eye under said standard wearing condition, so as to slow down the development of refractive error of the eye.

[0127] The second optical function of at least a portion of the optical element may be an aspherical optical function.

[0128] The two optical functions differ at least in that their optical powers differ from one another. Two optical powers are different in the sense of the invention if the absolute value of the difference between them is greater than or equal to 0.25 diopters.

[0129] The optical elements comprised in the optical device may be continuous.

[0130] In the context of the present disclosure, two optical elements are considered to be continuous if there is a path connecting them along which at least one optical power can be measured under standard wearing conditions, which at least one optical power is different from the optical power based on the wearer's prescription for correcting the refractive error of the wearer's eye.

[0131] In the context of the present disclosure, all optical elements being continuous is to be understood as an optical system on which both optical functions of the optical elements can be measured at all points of the optical system.

[0132] For an optical system or device in which all optical elements are identical and recur periodically, for each of these optical elements, the profile of this optical element and therefore the "center" (optical center or geometric center, such as centroid) of this optical element can be determined. These optical elements are considered "continuous" if the distance between the centers (C1, C2) of these optical elements is less than the dimension of the optical element in the C1C2 direction.

[0133] Each optical element in the plurality of optical elements is transparent across the entire visible spectrum.

[0134] The centres of at least a part, for example all, of the optical elements may be arranged on a predefined array of spots, for example an array of spots comprising spots arranged in a square or hexagon or an array comprising randomly positioned spots.

[0135] Advantageously, the inventors have observed that for a given density of optical elements, arranging at least a portion, such as all, of the optical elements along a plurality of concentric rings increases the overall acuity of the lens element. For example, having a distance D greater than 2.00 mm between two adjacent concentric rings of optical elements allows managing a larger area between these optical element rings, thus providing better overall visual acuity.

[0136] The optical element may cover a specific area of ​​the optical system, such as the center or any other area of ​​the optical lens, such as the periphery.

[0137] According to an embodiment, the optical device may have regions without optical elements, eg said regions comprising control points.

[0138] For example, a disk centered on the fitting cross and having a radius greater than 1.5 mm, such as greater than 2 mm and less than 5 mm, may be free of optical elements.

[0139] Depending on the design requirements, different parts of the lens element may be free of optical elements.

[0140] According to a preferred embodiment of the present disclosure, the optical lens is an edged optical lens intended to be mounted in a spectacle frame, and the entire surface of at least one face of the optical lens is covered with a plurality of optical elements.

[0141] Examples of such embodiments are Figure 2 As shown, the face of the lens element is completely covered with a plurality of continuous diffractive optical elements.

[0142] Optical element density or amount of focus may be adjusted according to the zone of the optical device. Typically, optical elements may be positioned at the periphery of the optical device in order to increase the effect of the optical elements on myopia control, compensating for peripheral defocus due to, for example, the peripheral shape of the retina.

[0143] Optical elements can be manufactured using different techniques, such as direct surface treatment, molding, casting or injection, embossing, film formation or photolithography, etc. According to the present invention, photolithography may be particularly advantageous, especially if one of the surfaces of the optical device is flat, or a master is manufactured to replicate a film or wafer.

[0144] According to an embodiment of the present invention, at least one, for example, all optical elements are configured to form a focal point in front of the retina of a person's eye. In other words, such optical elements are configured so that each segment plane (if any) where the light flux is concentrated is located in front of the retina of the person's eye.

[0145] According to an embodiment of the present invention, at least one, for example all, optical elements are made of a material different from the optical lens. In particular, the refractive index of the optical element may be different from the refractive index of the material of the optical device.

[0146] According to an embodiment of the present invention, at least one, for example all, optical elements are made of birefringent materials. In other words, the optical elements are made of materials having a refractive index that depends on the polarization and propagation direction of the light. Birefringence can be quantified as the maximum difference between the refractive indices exhibited by the materials.

[0147] According to an embodiment of the present invention, at least a portion, for example all, of the optical elements are diffractive lenses within the visible spectrum (for example, wavelengths from 400 nm to 700 nm).

[0148] For example, at least a portion, such as all, of the optical elements are pixelated optical elements, such as pixelated lenses, wherein one out of every two pixels is associated with each optical function. Eyal Ben-Eliezer, Emanuel Marom, Naim Konforti, and Zeev Zalevsky disclose examples of pixelated lenses. Experimental implementation of an imaging system with extended depth of field. Appl. Opt., 44(14):2792-2798, May 2005.

[0149] According to an embodiment of the invention, at least one, for example all, of the optical elements have a discontinuity, such as a discontinuous surface, for example a Fresnel surface and / or have a discontinuous refractive index profile.

[0150] Figure 3 An example of a radial profile of a first diffractive optic that can be used in an optical element of the present invention is shown.

[0151] Figure 4 An example of a radial profile of a second diffractive lens that can be used in the optical element of the present invention is shown.

[0152] The diffractive lens may be a diffractive lens whose phase function ψ(r) has a π phase jump at the nominal wavelength λ0, such as Figure 5 For clarity, these structures can be named "π-Fresnel lenses" because they are in contrast to monofocal Fresnel lenses where the phase jump is a multiple of 2π. The phase function is Figure 5 The π-Fresnel lens shown in diffracts light primarily in two diffraction orders (0th and +1st) associated with a refractive power P(λ0)=0δ and a positive refractive power, for example P(λ0)=3δ, at λ0=550 nm.

[0153] The advantage of this design is that the diffraction order specific to the wearer's prescription is not colored, while the one diffraction order used to provide the second optical function to slow down myopia progression is clearly colored. Advantageously, this allows for increased wearer comfort.

[0154] Typical sizes of the optical element may be greater than or equal to 500 μm, preferably greater than or equal to 2 mm, and less than or equal to 5 mm, preferably less than or equal to 2.5 mm. In practice, the inventors have observed that it is advantageous to keep the size of the optical element smaller than the size of the pupil of the wearer's eye.

[0155] For example, the diffraction efficiency of the 0th and +1st orders is about 40% at the nominal wavelength λ0.

[0156] To improve the efficiency of the diffraction orders corresponding to the wearer's prescription, the following items may be considered.

[0157] In order to increase the efficiency of the 0th diffraction order, the value of λ0 can be reduced. Figure 6a shows the diffraction efficiency at λ0 = 550 nm and Figure 6b The diffraction efficiency at λ0=400nm is shown. One can note that in this case, the 0th order diffraction efficiency is generally higher over the entire visible spectrum, whereas the +1st order diffraction efficiency is lower. In this case, the diopter of the refractive phase function that applies a phase jump for λ0=550nm should be equal to 1.5*400 / 550≈1.1δ instead of Figure 5 1.5δ in the +1 order corresponds to a diopter of 3δ at λ0 = 550nm. This makes Figure 5 The ring widens.

[0158] Additionally or alternatively, Figure 5 Two configurations are shown with one ring set to zero. In this case, due to the remaining π-Fresnel rings, the two different functions still exist simultaneously, but the ring set to zero induces a larger fraction of the 0δ diopter.

[0159] One can further consider applying a π-Fresnel structure made of two materials with two different refractive indices and different Abbe numbers to obtain Figure 5 =λ0 and obtain a more uniform efficiency over the visible spectrum and / or make one of the two main diffraction orders more dominant over the other.

[0160] Other combinations with superimposed π-Fresnel structures are conceivable.

[0161] According to an embodiment of the present disclosure, at least one, for example all, of the optical elements are multifocal binary components, for example multifocal binary lenses.The binary lens may have a radial profile with a breakpoint height of about 1 μm.

[0162] For example, Figure 7a As shown in , the binary structure mainly shows two diopter powers, denoted as -P / 2 and P / 2, and corresponds to two main diffraction orders. Figure 7b When the refractive structure shown in is associated with P / 2, Figure 7c The final structure represented in has a refractive power of 0δ and P. The presented situation is associated with P=3δ.

[0163] Advantageously, the -1st and 1st order diffraction efficiencies are approximately 40% at nominal wavelength, and furthermore, the diffraction efficiency remains high throughout the visible spectrum, typically exceeding 35%.

[0164] According to an embodiment of the present disclosure, at least a portion, for example, all of the diffractive lenses include a metasurface structure (also known as a superlens).

[0165] For example, a lens element may include a simultaneous bifocal metalens array with P1 = 0δ and controlled chromatic aberrations for the diopters P1, P2.

[0166] In general, P1 = 0δ can be achromatic (which means that each wavelength has the same focus) or partially achromatic.

[0167] The chromatic aberration of P2 can be advantageously controlled, such as wavelength-dependent focal length and efficiency.

[0168] The chromatic aberration of each metalens may differ depending on the location of the metalens on the surface of the lens element (near vision zone, intermediate vision zone, or distance vision zone).

[0169] Each metalens itself can be made from an array of sub-wavelength elements:

[0170] For example, the sub-wavelength elements can have any shape (such as circular, rectangular, or elliptical), any size, can be equidistant, all aligned in the same direction, or rotated relative to each other.

[0171] The sub-wavelength elements of the metalens should be made of high-dielectric materials.

[0172] Each metalens can be made of a combination of "sub-metalens". For example, dual-focal properties can be obtained depending on the wavelength by spatial multiplexing or stacking of several sub-metalens.

[0173] Dual-focal properties can be obtained depending on the polarization by spatial multiplexing or stacking of several sub-metalenses.

[0174] According to an embodiment of the present disclosure, at least one, for example all, optical elements have an optical function including high-order optical aberrations. For example, the optical element is a micro-lens composed of a continuous surface defined by Zernike polynomials.

[0175] The invention also relates to an optical device intended to be placed on the surface of an optical lens in order to add the optical power of said optical lens, for example to form an optical system as disclosed herein, said optical device comprising a plurality of optical elements, wherein each optical element simultaneously has two different optical functions, while providing:

[0176] - a first optical power having an absolute value less than or equal to 0.25 diopters, and

[0177] - a second mean optical power greater than or equal to 0.5 diopters.

[0178] The optical element of the optical device may include any combination of features previously described in relation to the optical system.

[0179] Depending on the embodiment, the optical device may be rigid or flexible.As previously disclosed, the optical device may be one of a film, a path or a wafer.

[0180] The optical device may be attached to the surface of the optical lens by means of the inherent adhesive properties of the material constituting the optical device, or possibly by using a thin film of water between the two interfaces (the water film acting as a carrier to initiate contact between the optical device and the optical lens).

[0181] Therefore, in the present disclosure, the material constituting the optical device preferably combines transparent properties so that it can maintain the optical quality of the optical lens that will receive it, as well as adhesive properties and physical properties that allow the optical device to have a certain flexibility so as to adapt it to the radius of curvature of the optical component to which it will be attached.

[0182] Advantageously, the material constituting the optical device of the present disclosure has a Shore A hardness between 70 and 95 and a light scattering percentage between 2.0% and 0.4%, preferably less than 1%.

[0183] The material that can be used in the context of the present disclosure can in particular be a transparent thermoplastic material, for example selected from the polymers polyurethane, polyvinyl chloride, polyethylene terephthalate, poly(methyl methacrylate) and polycarbonate. Preferably, the material constituting the optical device is selected from polyurethane thermoplastics and polyvinyl chloride thermoplastics.

[0184] The material of the optical lens can be inorganic or organic. As a non-limiting example, the organic material that can be used in the context of the present disclosure can be a material conventionally used in optics and ophthalmology. For example, suitable materials are substrates such as: polycarbonate; polyamide; polyimide; polysulfone; poly(ethylene terephthalate) and polycarbonate copolymers; polyolefins, especially polynorbornene; diethylene glycol bis(allyl carbonate) polymers and copolymers; (meth) acrylate polymers and copolymers, especially polymers and copolymers of (meth) acrylate derivatives of bisphenol A; thio(meth) acrylate polymers and copolymers; polymers and copolymers of urethane and thiourethane; epoxy polymers and copolymers and episulfide polymers and copolymers.

[0185] The invention has been described above by means of embodiments without limiting the general inventive concept.

[0186] Numerous further modifications and variations will be apparent to those skilled in the art upon reference to the foregoing illustrative embodiments, which are presented by way of example only and are not intended to limit the scope of the invention, which is determined solely by the appended claims.

[0187] In the claims, the word "comprising" does not exclude other elements or steps and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope of the invention.

Claims

1. An optical system intended to be worn in front of a wearer's eye, the optical system comprising: - an optical lens having at least one control point, and - an optical device comprising a plurality of optical elements, the optical device being attached to the surface of the optical lens or being encapsulated in the optical lens, in, - The control points include any of the following: ○ Areas without optical components, and / or ○The geometric center of the optical lens, and / or ○The optical center of the optical lens, and / or ○ In the case of progressive ophthalmic lenses: ■Mirror cross, or ■Distance reference point, or ■ Near reference point, -Each optical element has two different optical functions at the same time, - wherein the first optical function of at least a portion of the optical elements is such as to focus an image on the central retina of the eye, regardless of the eye gaze direction, when the optical system is worn under standard wearing conditions, - wherein the second optical function of at least a portion of the optical elements is to focus an image not on the retina of the eye in the standard wear but in front of or behind the wearer's retina in peripheral vision, - the optical device and the optical lens are configured so that the absolute value of the difference between the optical power measured at the control point of the optical system and the optical power corresponding to the prescription of the eye of the wearer is less than or equal to 0.12 diopters.

2. An optical system according to claim 1, wherein the optical system is configured such that, for at least one optical element, the absolute value of the difference between at least one optical focal length measured through the optical element of the optical system and the optical focal length measured only through the corresponding part of the optical lens is less than or equal to 0.25 diopters.

3. The optical system according to claim 1 or 2, wherein: The first optical function is an optical function having an average optical power less than or equal to 0.25 diopters.

4. An optical system according to any one of claims 1 to 3, wherein: The second optical function of at least a portion of the optical elements has an average optical power greater than or equal to 0.5 diopters.

5. An optical system according to any one of the preceding claims, wherein: The second optical function of at least a portion of the optical elements is such that the image is not focused on the retina of the eye when the optical system is worn under standard wearing conditions to slow down the progression of refractive error in the eye.

6. An optical system according to any one of the preceding claims, wherein: The optical device is attached to the front surface of the optical lens or the rear surface of the optical lens or is inserted into the interior of the optical lens.

7. An optical system according to any one of the preceding claims, wherein: At least a portion of the optical element is continuous.

8. An optical system according to any one of the preceding claims, wherein: At least a portion of the optical elements are arranged along a plurality of concentric rings.

9. An optical system according to any one of the preceding claims, wherein: At least a portion of the optical elements are diffractive lenses.

10. An optical system according to any one of the preceding claims, wherein: At least a portion of the optical elements are π-Fresnel lenses.

11. An optical system according to any one of the preceding claims, wherein: The optical elements have a square or hexagonal outline and are arranged according to a predefined array.

12. An optical device intended to be placed on the surface of an optical lens in order to add optical power to the optical lens, the optical device comprising a plurality of optical elements, wherein: Each optical element performs two different optical functions simultaneously, providing: - a first mean optical power having an absolute value less than or equal to 0.25 diopters, and - a second mean optical power greater than or equal to 0.5 diopters.

13. A method for providing an optical system intended to be worn in front of an eye of a wearer, wherein: The method comprises the following steps: - providing an optical lens configured to provide a corrective optical power to the wearer under standard wearing conditions based on the wearer's prescription for correcting ametropia of the eye of the wearer, - providing an optical device according to claim 12, - forming an optical system by placing the optical device on one surface of the optical lens or by encapsulating the optical device into the optical lens.

14. A method for providing an optical system intended to be worn in front of an eye of a wearer, wherein: The method comprises the step of casting the optical system and during the casting step providing an optical device according to claim 12 for insertion into the cast lens.

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