Method for providing a lens element

Abstract

A method for providing a lens element comprising a plurality of encapsulated diffractive microstructures, the method comprising: (S2) obtaining first lens component data relating to a shape and a refractive index of a first lens component comprising a plurality of diffractive microstructures; (S4) obtaining second lens member data relating to the shape and refractive index of a second lens member having a surface complementary to the surface of the first lens member comprising the plurality of diffractive microstructures; (S6) generating a lens element model based on the first lens member data and the second lens member data; (S3) obtaining energy balance data relating to at least two maximum MTF levels in at least two different planes (z1, z2); (S10) optimizing the lens element model based on the energy balance data; and (S12) providing the lens element by assembling at least the first lens member and the second lens member based on the optimized lens element model.

Description

Technical Field

[0001] This disclosure relates to a method for providing a lens element, and more specifically, to a method for obtaining a lens element comprising a plurality of encapsulated diffractive microstructures, and a lens element obtained using said method. Background Technology

[0002] Over the years, the design of optical lenses has become increasingly complex. This increased complexity makes their manufacturing process more difficult.

[0003] Recent advancements in controlling myopia progression have led to a significant increase in the number of optical lens designs that incorporate microlenses. The purpose of these microlens arrays is to provide an optically blurred image not on the retina, but rather in front of it, thereby triggering a stop signal that limits eye growth while still achieving good vision.

[0004] Although these myopia control lenses have extremely complex surface shapes involving very small features, they are typically manufactured using common processes such as molding or grinding. However, to obtain lenses with different levels of myopia control, lens manufacturers have to use a much wider range of molds, which are expensive to build and store. Similarly, the increased time required to grind the lens element surface to obtain these very small features also increases the risk of errors and deviations from the target.

[0005] Similarly, personalizing lens elements to better suit the wearer and / or a particular eyeglass frame often increases the complexity of the lens element manufacturing process.

[0006] Therefore, there is a need to provide a solution to simplify the process, thereby providing a wide range of lens elements with different optical functions. Summary of the Invention

[0007] Therefore, this disclosure proposes a method for providing a lens element comprising multiple encapsulated diffractive microstructures, the method comprising:

[0008] - Obtain first lens component data, which includes at least data related to the shape of the first lens component and the first refractive index n1 of the first lens component, wherein at least one surface (F1) of the first lens component includes multiple diffraction microstructures.

[0009] - Obtain data on a second lens component, which includes at least data relating to the shape of the second lens component and the second refractive index n2 of the second lens component, the second lens component including at least one surface (F2) complementary to the surface of the first lens component including the plurality of diffraction microstructures.

[0010] - A lens element model is generated based on the data of the first lens component and the second lens component. This lens element model is formed by bonding the complementary surfaces of the first lens component and the second lens component together.

[0011] - Obtain energy balance data, which includes data related to at least two maximum MTF levels in at least two different planes (z1, z2).

[0012] - Optimize the lens element model based on energy balance data by changing at least one of the first refractive index n1 of the first lens element and the second refractive index n2 of the second lens element, such that at least two maximum MTF levels can be measured in at least two different planes (z1, z2) at at least one pupil of at least a portion of the plurality of diffraction microstructures surrounding the lens element.

[0013] - A lens element is provided by assembling at least a first lens element and a second lens element based on an optimized lens element model.

[0014] Advantageously, this method allows for the provision of a wide range of lens elements with different optical properties without requiring modification of the surface design of the lens elements. In fact, the inventors have observed that changing the refractive index difference of the materials used to form the lens elements allows for alteration of the optical properties of the lens elements.

[0015] According to other embodiments that can be considered individually or in combination:

[0016] - The method further includes providing prescription data, which is at least related to a prescription suitable for the wearer; and manufacturing an ophthalmic lens from a lens element based on the prescription data; and / or

[0017] - During the manufacturing process of the ophthalmic lens, at least one surface of the lens element is modified such that a first plane z1 on the pupil in which the maximum MTF level can be measured coincides with the plane of the wearer's retina; and / or

[0018] - During the manufacturing process of an ophthalmic lens, at least one surface of the lens element is modified such that a second plane z2, in which the maximum MTF level can be measured on the pupil, is located in front of or behind the plane of the wearer's retina; and / or

[0019] - At least a portion, for example, all of the multiple diffraction microstructures, are microlens arrays; and / or

[0020] - These small lenses are arranged across the entire surface of the lens element; and / or

[0021] - At least some, for example, all of these small lenses are non-contiguous; and / or

[0022] - At least some, for example, all of these small lenses are adjacent; and / or

[0023] - These small lenses have an external shape circumscribed by a circle with a diameter less than or equal to 3.0 mm, for example less than or equal to 1.5 mm, for example less than or equal to 1.0 mm, and the diameter of their largest inscribed circle is greater than or equal to 0.1 mm, for example greater than or equal to 0.6 mm; and / or

[0024] - These small lenses are arranged in concentric rings; and / or

[0025] - At least a portion, preferably all of the plurality of diffraction microstructures, are diffraction microlenses; and / or

[0026] - At least some, preferably all, of these diffractive microlenses are π-Fresnel microlenses; and / or

[0027] - The at least two maximum MTF levels measured in planes z1 and z2 correspond to the first-order and second-order diffraction of the π-Fresnel microlens; and / or

[0028] - At least one of the first lens component or the second lens component is a sheet, a film, an adhesive layer, or a coating layer; and / or

[0029] This disclosure further relates to a lens element comprising multiple encapsulated diffractive microstructures obtained using the method according to this disclosure. Attached Figure Description

[0030] Embodiments of the invention will now be described by way of example only with reference to the following accompanying drawings, in which:

[0031] - Figure 1 A schematic outline view of a lens element according to an embodiment of the present disclosure is illustrated;

[0032] - Figures 2A to 2C A schematic outline view of a lens element according to an embodiment of the present disclosure is illustrated;

[0033] - Figure 3 A schematic front view of a lens element according to an embodiment of this disclosure is illustrated;

[0034] - Figure 4 The illustration shows a schematic front view of a lens element according to an embodiment of this disclosure; and

[0035] - Figure 5A flowchart illustrating a method for providing a lens element according to an embodiment of this disclosure is shown.

[0036] The elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the figures may be enlarged relative to other elements to help improve the understanding of embodiments of the invention. Detailed Implementation

[0037] In the remainder of this instruction manual, terms such as “upper,” “bottom,” “horizontal,” “vertical,” “above,” “below,” “front,” “back,” or other words indicating relative position may be used. These terms should be understood in the context of wearing the optical lenses.

[0038] This disclosure relates to a method for providing a lens element comprising multiple diffractive microstructures.

[0039] In the context of this invention, the term "lens element" may refer to a lens blank, or a semi-finished lens, or an optical lens, or an eyeglass optical lens that has been edged to fit a particular eyeglass frame, or an ophthalmic lens, or an optical device suitable for positioning on an ophthalmic lens, film, or sheet.

[0040] like Figure 1 As indicated, the lens element 10 is formed by at least a first lens component 12a and a second lens component 12b.

[0041] The first lens component 12a may include an eye-side surface formed as a concave surface and a surface F1 opposite to the eye-side surface. The second lens component 12b may include an object-side surface formed as a convex curved surface facing the object side and a surface F2 opposite to the object-side surface. Alternatively, the object-side surface and / or the eye-side surface may be any of a plano surface, a convex surface, or a concave surface. Surface F1 of the first lens component 12a and surface F2 of the second lens component 12b are complementary surfaces. Both complementary surfaces F1 and F2 are designed to fit precisely into the other to ensure a tight and secure fit when the two lens components are placed together.

[0042] At least one complementary surface F1 or F2 includes multiple diffraction microstructures 14. Figure 1In the illustrated embodiment, the diffraction microstructure 14 is disposed on surface F1 of the first lens member 12a. However, it should be understood that the plurality of diffraction microstructures can be disposed on any complementary surface F1 and / or complementary surface F2. The plurality of diffraction microstructures can be directly engraved, imprinted, etched, molded, or embossed onto the surface of the lens member. When the complementary surfaces F1 and F2 are placed together, the plurality of diffraction microstructures are encapsulated within the lens element. In the context of this invention, "encapsulated" should be understood as being surrounded, wrapped, protected internally, or isolated from the outside, as if in a capsule.

[0043] The lens element may further include at least one additional lens element disposed on either the first or second lens element. For example, the lens element may include a third lens element that forms a coating layer disposed on the object-side surface of the second lens element. Another lens element may be a support sheet disposed on the eye-side surface of the first lens element. The additional lens element may be made of a material common to at least one of the first or second lens elements and therefore have the same refractive index. Alternatively, the additional lens element may be made of a different material from the first and second lens elements and therefore have a different refractive index.

[0044] The first lens component and / or the second lens component may be a lens film, a film, an adhesive layer, a coating element layer, or a resin layer.

[0045] In the example illustrated in Figure 2a, the first lens component 12a is a lens sheet made of a first material having a first refractive index n1, and the second lens component 12b is a lens sheet made of a second material having a second refractive index n2. The complementary surface F1 of the first lens component 12a includes a plurality of diffraction microstructures 14 made of the same first material.

[0046] Lens films are typically obtained through conventional molding processes (e.g., injection molding or casting molding). In a non-limiting example, a first lens component 12a is first manufactured by injecting a first material into a first master mold and pressing it against a microstructure pattern on the first master mold. By hot pressing, the reverse structure of the pattern is transferred to the surface of the first lens component 12a to form the plurality of diffraction microstructures 14. The manufactured first lens component 12a is further introduced into a second master mold, and a second material is injected and molded over the first lens component to form a second lens component 12b.

[0047] In the example illustrated in Figure 2b, the first lens component 12a is a film made of a first material having a first refractive index n1, on which a plurality of diffraction microstructures 14 have been imprinted (e.g., using conventional photolithography techniques) or ground. The first lens component 12a is disposed on an additional third lens component 12c, which is a support lens sheet. An adhesive layer is further added to the first lens component to hold the first lens component on the support lens sheet. This adhesive layer forms a second lens component 12b made of a second material having a second refractive index n2.

[0048] In the example illustrated in Figure 2c, the first lens component 12a is directly imprinted onto the surface of an additional third lens component 12c (e.g., a supporting lens sheet) using a first material having a first refractive index n1. A coating layer is further applied over the first lens component 12a, for example, using common techniques such as casting, overmolding, or imprinting. This coating layer forms a second lens component 12b made of a second material having a second refractive index n2.

[0049] The first lens component and / or the second lens component can be made of any suitable material, such as mineral materials (like glass) or organic materials (like plastics, resins, epoxy resin adhesives, hot melt adhesives, UV adhesives, pressure-sensitive adhesives, rubber). For example, the material of the first lens component and / or the material of the second lens component can be any of the following: polycarbonate, copolyester, thermoplastic polyurethane, poly(methyl methacrylate), polyamide, bioengineered polymer, cellulose triacetate, allyl diethylene glycol carbonate, polycyclic sulfide, Trivex, polyacrylic acid, polyol, polyamine, polyanhydride, polycarboxylic acid, polyepoxide, polyisocyanate, polynorbornene, polysiloxane, polysilazane, polystyrene, polyolefin, polyester, polyimide, polyurethane, polythiourethane, polyallyl, polysulfide, polyethylene ester, polyethylene ether, polyaryl, polyoxide, polysulfone, polycyclic olefin, polyacrylonitrile, polyethylene terephthalate, polyetherimide, polypentene, acrylate, polyurethane, styrene copolymer, CR39, MR7, MR8, 1.74, 1.56, etc., as well as materials used for adhesives, PSA, coatings, etc.

[0050] The refractive indices n1 and n2 of the materials used for the corresponding first and second lens components can be appropriately selected to obtain the target optical properties of the lens elements. Preferably, the first refractive index n1 and the second refractive index n2 are different. Preferably, when measured at a wavelength of 550 nm, the first refractive index n1 and the second refractive index n2 are between 1.3 and 1.7. For example, the first refractive index n1 and the second refractive index n2 may be less than or equal to the following values, or between any two of the following values: 1.9; 1.8; 1.75; 1.73; 1.71; 1.69; 1.67; 1.65; 1.63; 1.61; 1.59; 1.57; 1.55; 1.54; 1.53; 1.52; 1.51; 1.50; 1.49; 1.48; 1.47; 1.46; 1.45; or lower, and / or greater than or equal to the following values, or between any two of the following values: 1.1; 1.2; 1.25; 1.3; 1.31; 1.33; 1.35; 1.37; 1.39; 1.41; 1.43; 1.45; or higher.

[0051] The eye-side surface of the first lens element and / or the object-side surface of the second lens element can have any suitable shape, such as a spherical shape or a non-spherical shape. The term "spherical shape" refers to the curvature of a lens surface that closely follows the shape of a perfect or near-perfect sphere. A spherical surface has a substantially uniform curvature across the entire surface of the lens element, which remains substantially the same along all meridians. A "non-spherical surface" should be understood as non-uniform across the entire surface of the lens element, having different curvatures along different meridians.

[0052] The eye-side surface of the first lens component and / or the object-side surface of the second lens component may have a toric shape. A toric surface has two principal meridians perpendicular to each other, often referred to as a “steep” meridian and a “flat” meridian. The curvature of the surface is different along these meridians.

[0053] The eye-side surface of the first lens component and / or the object-side surface of the second lens component may have an aspherical shape. The curvature of the aspherical surface changes gradually across the surface of the lens element. The curvature along different meridians changes from the geometric center of the lens element toward the periphery; for example, the curvature of the surface increases or decreases toward the peripheral portion of the surface. The shape of the aspherical surface is typically described using mathematical equations (such as conic section equations or polynomial equations).

[0054] The eye-side surface of the first lens component and / or the object-side surface of the second lens component may have a progressive multifocal lens profile. In the sense of this disclosure, a “progressive multifocal lens profile surface” should be understood as a surface comprising two regions with different spherical surfaces and a third region connecting the two first regions, the curvature value of which changes from the first curvature value of the corresponding two regions to a second curvature value along the third region.

[0055] Alternatively, the eye-side surface of the first lens component and / or the object-side surface of the second lens component may have a plano shape. A plano surface has no curvature across the entire surface of the lens element.

[0056] like Figure 1 As illustrated, at least one of the first lens component 12a and / or the second lens component 12b includes a plurality of diffraction microstructures.

[0057] These multiple diffraction microstructures are designed to provide the optical function of diffracting or deflecting light in a specific manner. For example, the diffraction microstructures can control the phase and amplitude of the diffracted light, thereby modifying the shape of the incident beam to a single focal point. Alternatively, the diffraction microstructures can be used to split a single incident beam into multiple beams and redirect those multiple beams along different paths, thereby producing a blurred or unfocused volume of light.

[0058] like Figure 3 As illustrated, the plurality of diffraction microstructures 14 can be a plurality of small lens arrays.

[0059] The small lens has an external shape circumscribed by a circle with a diameter less than or equal to 3.0 mm, for example less than or equal to 2.5 mm, preferably less than or equal to 2.0 mm, more preferably less than or equal to 1.5 mm, for example less than or equal to 1.0 mm. The small lens may be further characterized in that the diameter of its largest inscribed circle is greater than or equal to 0.1 mm, preferably greater than or equal to 0.2 mm, more preferably greater than or equal to 0.4 mm, and even more preferably greater than or equal to 0.5 mm, for example greater than or equal to 0.6 mm.

[0060] like Figure 3 This means that at least a portion, for example more than 50%, and preferably all of the small lenses 14 may be contiguous.

[0061] like Figure 4 This means that at least a portion, for example more than 50%, and preferably all of the small lenses 14 may be non-contiguous.

[0062] In the sense of this disclosure, if there exists a path that supports and connects two microlenses located on the surface of the lens element, and if the base surface of the lens element on which the microlenses are superimposed cannot be reached along the path, then the two microlenses are adjacent.

[0063] When the surface on which at least two small lenses are stacked is spherical, the base surface corresponds to the spherical surface. In other words, if there exists a path that is supported by and connects two small lenses stacked on the spherical surface, and if the spherical surface may not be accessible along the path, then the two small lenses are adjacent.

[0064] When the surface on which at least two small lenses are superimposed is not spherical, the base surface corresponds to a locally spherical surface that best fits the non-spherical surface. In other words, if there exists a path that is supported by a non-spherical surface and connects two small lenses superimposed on the non-spherical surface, and if it is not possible to reach the spherical surface that best fits the non-spherical surface along the path, then the two small lenses are adjacent.

[0065] The density of microlenses on the lens element is between 20% and 100%, preferably between 30% and 70%, for example, between 40% and 50%. For example, for each circular region with a radius between 2 mm and 4 mm (the distance between its geometric center and the optical center of the lens element is greater than or equal to the radius + 5 mm), the ratio between the sum of the areas of the portions of the microlenses located within the circular region and the area of ​​the circular region is between 20% and 100%, preferably between 30% and 70%, for example, between 40% and 60%.

[0066] like Figure 4 As illustrated, the small lenses 14 can be arranged on the entire surface of the lens element 10. In other words, the ratio between the sum of the projected areas of the lens element covered by the small lenses and the total area is equal to 1.

[0067] Small lenses can be positioned on structured meshes, such as square meshes, hexagonal meshes, triangular meshes, or octagonal meshes.

[0068] like Figure 3 As illustrated, the small lenses can be arranged in multiple concentric rings centered on the optical center and / or geometric center of the surface on which these small lenses are disposed of of the lens component.

[0069] The radial distance between the two successive concentric rings of the microlens can be the same. Alternatively, the radial distance between the two successive concentric rings of the microlens can vary. Preferably, the distance between the two successive concentric rings of the microlens is greater than or equal to 1.00 mm, preferably 2.0 mm, and more preferably 4.0 mm.

[0070] The diffraction microstructure 14 can be a diffraction microlens. In the sense of this disclosure, "diffraction microlens" should be understood as a small-scale optical element that acts as a miniature diffraction lens.

[0071] Diffractive microstructures can be π-Fresnel microlenses. In the context of this disclosure, a π-Fresnel microlens is a Fresnel microlens with a π-phase jump in the phase function ψ(r) at the nominal wavelength λ0, unlike a single-focus Fresnel lens where the phase jump is a multiple of 2π. π-Fresnel microlenses primarily diffract light to two diffraction orders (0th and +1st), for example, associated with diopter P(λ0) = 0δ and positive diopter P(λ0) = 3δ, where λ0 = 550 nm.

[0072] Advantageously, the π-Fresnel miniature lens allows the incident light to be diffracted toward two different planes, thus providing two different optical powers.

[0073] like Figure 5 As illustrated, the method for providing a lens element according to this disclosure includes step S2 of obtaining first lens component data.

[0074] The first lens component data includes at least data relating to the shape of the first lens component having a surface (F1) including diffraction microstructures and the first refractive index n1 of the first lens component. In the sense of this disclosure, the “shape” of the first lens component should be understood as allowing for parameter values ​​and / or equations that define the structure of the first lens component, such as the curvature of the surface of the first lens component and / or the thickness of the first lens component.

[0075] like Figure 5 As illustrated, the method for providing a lens element according to this disclosure includes step S4 of obtaining second lens component data.

[0076] Similar to the data for the first lens component, the data for the second lens component includes at least data relating to the shape of the second lens component and its second refractive index n2, wherein the second lens component has a surface (F2) complementary to the surface (F1) of the first lens component, which includes a plurality of diffraction microstructures. For the purposes of this disclosure, the “shape” of the second lens component should be understood as allowing for parameter values ​​and / or equations that define the structure of the second lens component, such as the curvature of the surface of the second lens component and / or the thickness of the second lens component.

[0077] like Figure 5 As illustrated, the method for providing a lens element according to this disclosure further includes step S6 of generating a lens element model.

[0078] In the context of this disclosure, a “lens element model” is a simulation, simplified representation, or mathematical description of the behavior and characteristics of a lens element. A lens element model is a theoretical framework that allows for the analysis and prediction of how light interacts with a lens element and how the lens affects light propagation. Typically, optical lens models are based on several fundamental principles of optics, including geometrical optics and wave optics.

[0079] Advantageously, the lens element model accurately simulates the optical characteristics of the lens element.

[0080] The lens element model is generated based on data from the first lens component and data from the second lens component. Using data related to the shape and refractive index of the lens components, the lens element model is generated by simulating the two lens components and attaching their complementary surfaces (F1) and (F2) together.

[0081] like Figure 5 The illustrated method for providing a lens element according to this disclosure further includes step S8 of obtaining energy balance data.

[0082] The energy balance data includes at least two maximum modulation transfer function (MTF) levels related to the lens element model in at least two different planes (z1, z2).

[0083] Modulation transfer function (MTF) is a well-known quantitative measure describing the imaging performance of an optical system. MTF characterizes the ability of an optical system to reproduce fine details and resolve spatial frequencies. It measures contrast transfer as a function of the spatial frequency of the imaged object and provides information about the resolving power of the optical system and the amount of contrast attenuation at different spatial frequencies.

[0084] Typically, a high MTF value indicates that an optical system can effectively reproduce high-frequency details with minimal contrast loss, resulting in a sharp and detailed image. Conversely, a low MTF value indicates that contrast decreases and fine details are lost as the spatial frequency increases.

[0085] The modulation transfer function can be determined by: measuring the 3D surface of the lens element; determining a 2D representation of the optical path difference of a beam perpendicular to the lens element; determining the point spread function on the pupil aperture, which has, for example, a diameter between 2 mm and 8 mm, preferably between 3 mm and 6 mm, such as 4 mm, and whose center is 6.6 mm away from the optical center of the lens element; and determining the modulation transfer function on the pupil by Fourier transform operation.

[0086] Advantageously, using lens models provides an efficient and convenient way to determine the MTF curve of a lens element without the involvement of the wearer or the eye-lens optics system.

[0087] Energy balance data represents the predefined or target locations of the two planes (z1, z2) in which the clearest image of an object passing through the lens element is obtained (i.e., the two planes from which the maximum MTF value can be obtained). These two planes (z1, z2) are parallel to the normal planes that are tangent to the optical center and / or geometric center of the lens element.

[0088] When the diffraction microstructure is a π-Fresnel microlens, the at least two maximum MTF levels measured in planes z1 and z2 correspond to the first-order diffraction 0 and the second-order diffraction +1 of the π-Fresnel microlens, respectively.

[0089] like Figure 5 The illustrated method for providing a lens element according to this disclosure further includes step S10 of optimizing a lens element model. The lens element model is optimized based on energy balance data.

[0090] During the optimization step, the lens element model is optimized by modifying, refining, and improving the data for the first and second lens components. Typically, the parameter values ​​and / or equations defining the structure of the first and / or second lens components are modified to obtain the target optical properties.

[0091] Preferably, at least one of the first refractive index n1 of the first lens component and / or the second refractive index n2 of the second lens component is changed such that at least two target maximum MTF levels defined by energy balance data can be measured in at least two different planes (z1, z2) at at least one pupil of at least a portion of the plurality of diffractive microstructures surrounding the lens component.

[0092] Advantageously, optimizing the refractive index of at least one lens element allows for easy tuning of the optical function of the lens element while preserving its initial surface design. In fact, the inventors have observed that modifying a combination of the refractive indices of two lens elements allows for a wide range of diffraction profiles of the lens element.

[0093] like Figure 5 As illustrated, the method for providing a lens element according to this disclosure further includes step S12 of providing the lens element.

[0094] The lens element is obtained by fabricating and assembling a first lens component and a second lens component based on an optimized lens element model. Alternatively, the first lens component and / or the second lens component may be selected from a series of prefabricated lens components. The first and second lens components are assembled such that a diffraction microstructure is encapsulated between the first and second lens components.

[0095] like Figure 5 The illustrated method for providing a lens element according to this disclosure may further include step S14 of providing prescription data. The prescription data relates at least to a prescription suitable for the wearer.

[0096] The term "prescription" should be understood as a set of optical characteristics, including power, astigmatism, and prism deviation, determined by an ophthalmologist or optometrist to correct visual defects, for example, by means of a lens positioned in front of the wearer's eye. For example, a prescription for myopia includes a power value and an astigmatism value with an axis for distance vision. A prescription may include an indication that the wearer's eye is not defective and will not provide the wearer with refractive power.

[0097] In addition to power prescriptions, prescriptions in ophthalmology can include astigmatism prescriptions. Such prescriptions consist of an axis value (in diopters) and a modulus value (in diopters). The modulus value represents the difference between the maximum and minimum power in a given direction, allowing for correction of the wearer's visual default. By convention, the axis represents the orientation of one of the two powers relative to a reference axis and following a given direction of rotation. The TABO convention can be used. In this convention, the reference axis is horizontal, and the direction of rotation is counterclockwise when looking at the wearer. A 45° axis corresponds to an axis that connects the upper right quadrant to the lower left quadrant when looking at the wearer with a tilted orientation. This astigmatism prescription is for measurements taken by the wearer at a distance. The term "astigmatism" is used to refer to a pair (modulus, axis). The term is sometimes used to specify only the modulus. Technicians readily understand what it refers to based on context. Technicians also recognize that a wearer's power / astigmatism prescription is often described using the terms "spherical power," "cylindrical power," and "axis."

[0098] Wearing conditions should be understood as the position of the lens element relative to the wearer's eye, defined by, for example, the tilt angle, the corneal-to-lens distance, and possibly the pupil-to-cornea distance, the eye rotation center (ERC)-to-pupil distance, and the ERC-to-lens distance.

[0099] 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 the first eye position (which is usually considered to be horizontal); for example, it is between 6 mm and 20 mm, for example, between 8 mm and 16 mm, preferably between 10 mm and 14 mm, and more preferably equal to 12 mm.

[0100] The pupil-to-corneal distance is the distance between the pupil and the cornea along the visual axis of the eye; it is usually between 1 mm and 4 mm, for example, equal to 2 mm.

[0101] The distance from the ERC to the pupil is the distance along the visual axis of the eye between its center of rotation (ERC) and the cornea; for example, it is between 10 mm and 15 mm, preferably between 11 mm and 12 mm, and more preferably equal to 11.5 mm.

[0102] The distance from the ERC to the lens Q'O is the distance between the ERC of the eye and the posterior surface of the lens along the visual axis of the eye in the first eye position (which is usually considered to be horizontal), for example, between 20 mm and 30 mm, preferably between 22.5 mm and 28 mm, and more preferably equal to 25.5 mm.

[0103] The tilt angle is the angle in a vertical plane between the intersection of the posterior surface of the lens and the visual axis of the eye in the first eye position (which is usually considered to be horizontal), between the normal of the posterior surface of the lens and the visual axis of the eye in the first eye position; for example, it is between -25° and +5°, preferably between -12° and 0°, more preferably between -10° and -6°, for example equal to -8° or 0°.

[0104] The wrap angle is the angle in the horizontal plane between the intersection of the posterior surface of the lens and the visual axis of the eye in the first eye position (which is usually considered to be horizontal), between the normal of the posterior surface of the lens and the visual axis of the eye in the first eye position, for example, between -10° and +25°, preferably between 0° and 10°, more preferably between 0° and +5°, for example equal to 0°.

[0105] Examples of standard wearing conditions can be defined by an anterior tilt angle of -8°, a corneal-to-lens distance of 12 mm, a pupil-to-corneal distance of 2 mm, an ERC-to-pupil distance of 11.5 mm, an ERC-to-lens distance of 25.5 mm, and a wrap angle of 0°.

[0106] Another example of standard wearing conditions more suitable for younger wearers can be defined by a 0° anterior tilt angle, a 12 mm corneal-to-lens distance, a 2 mm pupil-to-corneal distance, an 11.5 mm ERC-to-pupil distance, a 25.5 mm ERC-to-lens distance, and a 0° wrap angle.

[0107] Advantageously, a human prescription provides sufficient information to determine the position of the retina in a person's eye.

[0108] like Figure 5 The illustrated method for providing a lens element according to this disclosure may further include step S16 of manufacturing an ophthalmic lens. The lens element is manufactured based on prescription data to obtain an ophthalmic lens suitable for the wearer.

[0109] Typically, at least one of the eye-side surface of the first lens member and / or the object-side surface of the second lens member forming the lens element is processed (e.g., ground and edged) to modify the design of the lens element. Furthermore, a coating element layer may be applied to at least a portion, preferably all, of the surface of the lens element. This at least one coating element layer may include features selected from the group consisting of scratch-resistant, anti-reflective, dirt-resistant, dust-resistant, UV30 filtering, blue light filtering, and abrasion-resistant features.

[0110] Advantageously, encapsulating the diffraction microstructure between the first lens component and the second lens component allows for simplified manufacturing steps.

[0111] During the manufacturing process of an ophthalmic lens, at least one surface of the lens component can be modified such that a plane z1 on a predefined pupil, in which the maximum MTF level can be measured, coincides with the plane of the retina of the wearer to whom the lens is intended. In other words, at least one surface is manufactured such that when the wearer wears the ophthalmic lens under standard wearing conditions and looks directly at an object located at infinity, light from the object and passing through the diffraction microstructures and the eye will form a clear image on the retina of the eye.

[0112] Advantageously, this allows for the provision of ophthalmic lenses that improve the wearer's visual acuity.

[0113] During the manufacturing process of an ophthalmic lens, at least one surface of the lens component can be modified such that a plane z2, in which the maximum MTF level can be measured on a predefined pupil, is located in front of or behind the plane of the retina of the wearer to whom the lens is intended. In other words, at least one surface is manufactured to enable the ophthalmic lens to provide a blurred or defocused image to a wearer wearing the ophthalmic lens under standard wearing conditions.

[0114] Advantageously, providing a blurred or defocused image in front of or behind the retina allows for the generation of a stop signal that slows the progression of refractive errors in the wearer's eye.

[0115] This disclosure further relates to a computer program product including one or more stored instruction sequences accessible by a processor, the one or more stored instruction sequences causing the processor to perform the steps of the method according to this disclosure when executed by the processor.

[0116] This disclosure further relates to a computer-readable medium carrying one or more sequences of instructions for a computer program product according to this disclosure.

[0117] Furthermore, this disclosure relates to a program for causing a computer to execute the method disclosed herein.

[0118] This disclosure also relates to a computer-readable storage medium having a program recorded thereon; wherein the program causes a computer to execute the disclosure.

[0119] This disclosure further relates to an apparatus including a processor adapted to store one or more sequences of instructions and perform at least one step of the method according to this disclosure.

[0120] This disclosure further relates to a non-transitory program storage device that can be read by a computer, the non-transitory program storage device tangibly embodying a program having instructions that can be executed by a computer to perform the methods of this disclosure.

[0121] It will be apparent from the following discussion that, unless otherwise specifically stated, throughout this specification, the use of terms such as “operation,” “computation,” “generation,” etc., refers to the actions and / or processes of a computer or computing system or similar electronic computing device that manipulate and / or transform data represented as physical (e.g., electronic) quantities in the registers and / or memory of the computing system into other data similarly represented as physical quantities in the memory, registers, or other such information storage, transmission, or display devices of the computing system.

[0122] Embodiments of the present invention may include apparatus for performing the operations described herein. The apparatus may be specifically constructed for the desired purpose, or it may include a general-purpose computer or a digital signal processor (“DSP”) selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer-readable storage medium, such as, but not limited to, any type of disk, including floppy disks, optical disks, CD-ROMs, magneto-optical disks, read-only memory (ROM), random access memory (RAM), electronically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic cards or optical cards, or any other type of medium suitable for storing electronic instructions and capable of being coupled to a computer system bus.

[0123] The processes and displays presented herein are not inherently related to any particular computer or other device. Various general-purpose systems can be used with the programs taught herein, or it may prove convenient to build more specialized devices to perform the desired methods. The desired architecture of various such systems will become apparent from the description below. Furthermore, embodiments of the invention are described without reference to any particular programming language. It should be understood that the teachings of the invention described herein can be implemented using various programming languages.

[0124] Many further modifications and variations will be apparent to those skilled in the art when referring to the foregoing illustrative embodiments. These embodiments are given by way of example only and are not intended to limit the scope of this disclosure, which is defined only by the appended claims.

[0125] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plural. The mere fact that different features are described in mutually different dependent claims does not imply that combinations of these features cannot be used advantageously. Any reference numerals in the claims should not be construed as limiting the scope of this disclosure.

Claims

1. A method for providing a lens element comprising a plurality of encapsulated diffractive microstructures, the method comprising: (S2) Obtain first lens component data, the first lens component data including at least data related to the shape of the first lens component and the first refractive index n1 of the first lens component, at least one surface (F1) of the first lens component including a plurality of diffraction microstructures; (S4) Obtain second lens component data, the second lens component data including at least data related to the shape of the second lens component and the second refractive index n2 of the second lens component, the second lens component including at least one surface (F2) complementary to the surface of the first lens component including the plurality of diffraction microstructures. (S6) Generate a lens element model based on the first lens component data and the second lens component data. The lens element model is formed by bonding the complementary surfaces of the first lens component and the second lens component together. (S8) Obtain energy balance data, which includes at least data related to at least two maximum MTF levels in at least two different planes (z1, z2); (S10) Optimize the lens element model based on the energy balance data by changing at least one of the first refractive index n1 of the first lens element and the second refractive index n2 of the second lens element, such that at least two maximum MTF levels can be measured in at least two different planes (z1, z2) at at least one pupil of at least a portion of the plurality of diffraction microstructures surrounding the lens element. (S12) The lens element is provided by assembling at least the first lens component and the second lens component based on the optimized lens element model.

2. The method of claim 1, further comprising the step of providing prescription data (S14), the prescription data being at least related to a prescription suitable for the wearer; and the step of manufacturing an ophthalmic lens from the lens element based on the prescription data (S16).

3. The method according to claim 2, wherein, During the manufacturing process of the ophthalmic lens, at least one surface of the lens element is modified such that the first plane z1, in which the maximum MTF level can be measured on the pupil, coincides with the plane of the wearer's retina.

4. The method according to any one of claims 2 or 3, wherein, During the manufacturing process of the ophthalmic lens, at least one surface of the lens element is modified such that the second plane z2, in which the maximum MTF level can be measured on the pupil, is located in front of or behind the plane of the wearer's retina.

5. The method according to any one of the preceding claims, wherein, At least a portion of the plurality of diffraction microstructures is a microlens array.

6. The method according to claim 5, wherein, The small lenses are arranged on the entire surface of the lens element.

7. The method according to any one of claims 5 to 6, wherein, At least some, for example, all of the small lenses are non-contiguous.

8. The method according to any one of claims 5 to 6, wherein, At least some, for example, all of the small lenses are adjacent.

9. The method according to any one of claims 5 to 8, wherein, The small lens has an external shape circumscribed by a circle with a diameter less than or equal to 3.0 mm, for example less than or equal to 1.5 mm, for example less than or equal to 1.0 mm, and the diameter of its largest inscribed circle is greater than or equal to 0.1 mm, for example greater than or equal to 0.6 mm.

10. The method according to any one of claims 5 to 9, wherein, The small lenses are arranged in concentric rings.

11. The method according to any one of claims 1 to 10, wherein, At least a portion of the plurality of diffractive microstructures are diffractive microlenses.

12. The method according to claim 11, wherein, At least a portion, preferably all of the diffractive microlenses, are π-Fresnel microlenses.

13. The method according to claim 12, wherein, The at least two maximum MTF levels measured in the planes z1 and z2 correspond to the first-order and second-order diffraction of the π-Fresnel microlens.

14. The method according to any one of claims 1 to 13, wherein, At least one of the first lens component or the second lens component is a sheet, a film, an adhesive layer, or a coating layer.

15. A lens element comprising a plurality of encapsulated diffractive microstructures obtained using the method according to any one of claims 1 to 14.

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