Ophthalmic lenses adapted to correct and slow the progression of vision impairment

Abstract

The ophthalmic lens is adapted to correct a visual impairment and slow the progression of the visual impairment in the wearer's eye. The ophthalmic lens has a substrate, a front surface, and a back surface. The ophthalmic lens includes at least one pattern (10) of at least one optical element (12), and the difference between a first wavefront produced by a theoretical lens that solely corrects the visual impairment by prescription and a second wavefront produced by the ophthalmic lens forms a piecewise affine surface.

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to ophthalmic lenses adapted to correct and slow the progression of vision defects. [Background technology]

[0002] Visual impairment is sometimes defined by the eye's inability to image objects onto the retina. For example, in myopia, the eye images distant objects in front of the retina. Myopia is usually corrected with concave lenses. Myopia is usually corrected with concave lenses.

[0003] For simplicity, as a non-limiting example, only the example of myopia will be considered below, however the present disclosure also applies to other types of vision impairment.

[0004] It is now possible to slow myopia rather than simply correct it by providing ophthalmic lenses that contain predetermined microstructures, such as lenslets.

[0005] For example, US Pat. No. 5,629,999 discloses a lens with lenslets that compensate for some oblique astigmatism, such that for 30° off-axis angles the lenslets provide a point focus.

[0006] Lenslet-based myopia control solutions have proven their efficiency in clinical trials. However, they suffer from two main drawbacks: first, they are difficult to manufacture and measure; second, they have a significant impact on central vision.

[0007] Therefore, there is a need for an ophthalmic lens that is easy to manufacture and provides myopia control without significantly impacting central vision. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2019 / 166657 Brochure Summary of the Invention [Problem to be solved by the invention]

[0009] The purpose of the present disclosure is to overcome the above-mentioned shortcomings of the prior art. [Means for solving the problem]

[0010] To that end, the present disclosure provides an ophthalmic lens adapted to correct a visual defect and slow the progression of that visual defect in a wearer's eye, the ophthalmic lens having a substrate, a front surface and a back surface, and including at least one pattern of at least one optical element, wherein the difference between a first wavefront produced by a theoretical lens that solely corrects the visual defect by prescription and a second wavefront produced by the ophthalmic lens forms a piecewise affine surface.

[0011] The piecewise affine surfaces allow the optical element to provide a constant phase shift of light, and thus, their combined effect provides an image with reduced contrast at the retinal level. This phase shift results in myopia control due to the contrast reduction resulting from diffraction. Light travels different distances within the optical element depending on the angle of incidence, resulting in different phase shifts and therefore different contrast behavior. This allows for reduced contrast in peripheral vision for myopia control while preserving central vision as much as possible.

[0012] The present disclosure has many advantages. A simple manufacturing process can be used to produce such ophthalmic lenses. Furthermore, such ophthalmic lenses achieve different optical behavior depending on the angle of incidence, so that central vision is less affected than in prior art myopia-suppressing lenses. Furthermore, such ophthalmic lenses are compatible with anti-reflective coating steps or even hard coatings, so that no special inserts or molds are required to provide the above-mentioned patterns.

[0013] In one embodiment, at least one pattern is disposed on the front surface, and / or the back surface, and / or the substrate.

[0014] In one embodiment, the at least one optical element generates, on the exit pupil, a first phase shift of the second wavefront relative to the first wavefront that is less than a first predetermined value at a first angle of incidence of the light into the ophthalmic lens that corresponds to the wearer's central vision, and a second phase shift of the second wavefront relative to the first wavefront that is greater than a second predetermined value at a second angle of incidence of the light into the ophthalmic lens that corresponds to the wearer's peripheral vision.

[0015] In one embodiment, at least one pattern includes at least two optical elements, each of which generates, on the exit pupil, a first phase shift of a second wavefront relative to the first wavefront that is less than a first predetermined value at a first angle of incidence of the light onto the ophthalmic lens, corresponding to the wearer's central vision, and a second phase shift of the second wavefront relative to the first wavefront that is greater than a second predetermined value at a second angle of incidence of the light onto the ophthalmic lens, corresponding to the wearer's peripheral vision.

[0016] In one embodiment, the first predetermined value is 45° at an angle of incidence of 0°, and the second predetermined value is 90° at an angle of incidence of 30°.

[0017] In one embodiment, the at least one pattern is obtained by using a mask having holes corresponding to the pattern, depositing the pattern in the holes, and removing the mask.

[0018] In one embodiment, the mask is a laser cut sheet of metal.

[0019] In one embodiment, at least one optical element is made of a thin film stack.

[0020] In one embodiment, the thin film stack is a stack of successive layers of alternating low and high refractive index materials.

[0021] In one embodiment, the low refractive index material is SiO2 and the high refractive index material is ZrO2.

[0022] In one embodiment, the at least one optical element is made of a layer having a predetermined thickness that is deposited on the hard coat of the ophthalmic lens.

[0023] In one embodiment, the layer is deposited onto the hard coat by an inkjet process.

[0024] In one embodiment, the ophthalmic lens is obtained from a blank lens and at least one optical element is disposed on or within the blank lens.

[0025] In one embodiment, the ophthalmic lens is obtained from a finished lens and at least one optical element is disposed on or within the finished lens.

[0026] In one embodiment, the at least one pattern is included in the adhesive film.

[0027] In one embodiment, the portion of the ophthalmic lens comprising the at least one pattern of the at least one optical element and the remaining portion of the ophthalmic lens have the same or similar reflectance for wavelengths in the range of 380 nm to 780 nm, preferably 400 nm to 700 nm, more preferably 400 nm to 650 nm.

[0028] In one embodiment, the vision impairment is myopia.

[0029] For a more detailed understanding of the description provided herein and its advantages, reference is now made to the following brief description taken in conjunction with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a first non-limiting example of a pattern of an optical element according to the present disclosure. [Figure 2]2 is a graph showing a cost function corresponding to the pattern of FIG. 1; [Figure 3] 2 is a graph showing a cost function corresponding to the pattern of FIG. 1; [Figure 4] 1 is a second non-limiting example of a pattern of an optical element according to the present disclosure. [Figure 5] 5 is a graph showing a cost function corresponding to the pattern of FIG. 4. [Figure 6] 10 is a third non-limiting example of a pattern of an optical element according to the present disclosure. [Figure 7] 1 illustrates a particular embodiment of a lens including a phase-shifting pattern according to the present invention that can reduce myopia and also provide sun protection. [Figure 8] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 9] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 10] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 11] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 12] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 13] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 14] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 15] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 16] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 17] 8A-8C show non-limiting examples of coatings corresponding to the particular embodiment of FIG. 7. [Figure 18] FIG. 1 illustrates definitions of parameters used in this disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0031] In the following description, the making and use of various embodiments are discussed in detail below, but it should be understood that, as described herein, many inventive concepts are provided that can be embodied in a variety of contexts. The embodiments discussed herein are merely representative and do not limit the scope of the present disclosure. It will also be apparent to those skilled in the art that all technical features defined in relation to a process, individually or in combination, can be substituted for a device, and conversely, all technical features related to a device, individually or in combination, can be substituted for a process, and technical features of different embodiments can be interchanged or combined with features of other embodiments.

[0032] The terms "comprise" (and any grammatical variations thereof, such as "comprises" and "comprising"), "have" (and any grammatical variations thereof, such as "has" and "having"), "contain" (and any grammatical variations thereof, such as "contains" and "containing"), and "include" (and any grammatical variations thereof, such as "includes" and "comprising") are open-ended linking verbs. They are used to specify the presence of a stated feature, integer, step, or component, or group thereof, but do not exclude the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Consequently, a method or step in a method that "comprises," "has," "contains," or "includes" one or more steps or elements has those one or more steps or elements, but is not limited to having only those one or more steps or elements.

[0033] Ophthalmic lenses according to the present disclosure are adapted to correct and slow the progression of vision impairments in the wearer's eyes.

[0034] In a non-limiting example, the vision impairment may include myopia, although as noted above, the present disclosure also applies to other types of vision impairment.

[0035] The ophthalmic lens has a substrate, a front surface, and a back surface. Additionally, the ophthalmic lens includes one or more patterns of one or more optical elements such that the difference between a first wavefront produced by a theoretical lens that solely corrects a vision defect by prescription and a second wavefront produced by the ophthalmic lens forms a piecewise affine surface.

[0036] In certain embodiments, the optical element may introduce a constant phase shift. Define U(ξ,η) as the phase function produced by a regular single-vision lens, where ξ and η are the coordinates of the phase function in the plane of the exit pupil.

[0037] If an optical element produces a constant phase shift Φ for a given wavelength, say 550 nm, the additional phase factor is

number

number

[0038] In certain embodiments, one may attempt to calculate a constant phase shift such that the characteristics of the ophthalmic lens approximate those of a known control lens. For example, if a target myopia reduction lens has a pattern of optical elements with an add power P, the phase coefficient introduced by the optical elements can be calculated, in a second-order approximation, as follows:

number

[0039] The complete phase function is defined as follows:

number

[0040] Now consider an optical element that introduces a constant phase shift Φ 0 for a given wavelength, say 550 nm.

number

[0041] We find Φ for which the complex point spread function (PSF) of the newly defined optical element is as close as possible to the PSF of the optical element with addition power P. The PSF is obtained by the Fourier transform of the phase function defined above.

[0042] This involves minimizing a cost function, i.e.,

number

[0043] 1 shows a non-limiting example of a pattern 10 of optical elements 12 according to the present disclosure. The optical elements 12 are continuous circles, and the pattern 10 has a circular shape in the center where there are no optical elements in a hexagonal region H. The dark spot below the hexagonal region H represents the intersection of the light ray with the surface for a 15° drop in gaze direction with a 4 mm pupil size in central vision.

[0044] Figure 2 shows a plot of the corresponding cost function, revealing two minima symmetric about 180°. The abscissa axis is the phase shift Φ (in degrees). The pupil size is 4 mm.

[0045] The PSF is identical at Φ0=100° and Φ0=260°.

[0046] In another embodiment, instead of targeting the PSF in the cost function, the modulation transfer function MTF can be targeted to replicate the contrast modulation properties of the lenslet array.

[0047] In the embodiment, the following minimization is targeted:

number

[0048] FIG. 3 shows a plot of the corresponding cost function for the example pattern of FIG.

[0049] In that embodiment, in contrast to the PSF targeting approach, the cost function presents a much larger zone of acceptable phase shift values.

[0050] 4 shows another non-limiting example of a pattern 10 of optical elements 12 according to the present disclosure. The optical elements 12 are circles arranged in multiple concentric circles. A circular area C in the center of the pattern 10 is devoid of optical elements. The dark spot below the circular area C represents the intersection of the light ray with the surface for a 15° decrease in gaze direction with a 4 mm pupil size in central vision.

[0051] The corresponding cost function plot is shown in Figure 5. The pupil size is 4 mm. The cost function in Figure 5 is not as stable around the global minimum as the cost function in Figure 3.

[0052] The pattern 10 may have a non-circular contour, for example it may be a rectangular mesh defined by the following parameters: S x : horizontal step size, S y : vertical step size, W x : horizontal bandwidth, W y : vertical bandwidth, C x : horizontal offset, C y:Vertical offset.

[0053] The phase function of such a rectangular mesh can be defined as follows:

number

[0054] Figure 6 shows an example of a rectangular mesh with the following values: S x =s y =1.5mm w x =w y =1mm c x =c y =0.5mm φ0=100° The pupil size is 4 mm.

[0055] The angles of incidence used in the phase shift calculation can take into account the wearing conditions of the ophthalmic lens, such as pantoscopic and wrap angles, eye-lens distance, fitting cross position, and lens base curve. This information can be used to generate a set of normal and oblique angles of incidence corresponding to central and peripheral vision, respectively.

[0056] As a non-limiting example, the optical elements may be microstructures such as lenslets. The optical elements may have various shapes such as rings, or circles, or rectangles, or hexagons, or ellipses, or freeform surfaces, or NURBS (Non-Uniform Rational B-Spline Surfaces). This list of examples is not limiting.

[0057] At least one pattern may be disposed on the front surface, and / or the back surface, and / or the substrate.

[0058] At least one optical element is located immediately adjacent to the output of the lens, i.e., on the exit pupil, at the air-lens interface: a first phase shift of said second wavefront relative to said first wavefront that is lower than a first predetermined value, for example 45°, at a first angle of incidence of light on the ophthalmic lens, for example 0°, which corresponds to the wearer's central vision; a second phase shift of said second wavefront relative to said first wavefront that is higher than a second predetermined value, for example 90°, at an angle of incidence of said second light on the ophthalmic lens, for example 30°, corresponding to the peripheral vision of the wearer; Generate.

[0059] The first and second phase shift values ​​should be evaluated in the interval [0, 180°]. To do so, a phase shift should first be introduced in the interval [0, 360°] by adding multiples of 360°. Therefore, if the phase shift is between 0° and 180°, no addition step is performed. Otherwise, a symmetric value about 180° is selected.

[0060] In certain embodiments where at least one pattern includes at least two optical elements, each of the two optical elements is located immediately adjacent to the output of the lens, i.e., on the exit pupil located at the air-lens interface: a first phase shift of said second wavefront relative to said first wavefront that is lower than a first predetermined value, for example 45°, at a first angle of incidence of light on the ophthalmic lens, for example 0°, which corresponds to the wearer's central vision; a second phase shift of said second wavefront relative to said first wavefront that is higher than a second predetermined value, for example 90°, at an angle of incidence of said second light on the ophthalmic lens, for example 30°, corresponding to the peripheral vision of the wearer; Generate.

[0061] Here again, the first and second phase shift values ​​are considered in the interval [0, 180°] by following the procedure previously defined.

[0062] In other words, a sufficiently low shift can be provided at normal incidence to maintain visual acuity in central vision, and a sufficiently high shift can be provided at oblique incidence to reduce contrast in peripheral vision.

[0063] The at least one pattern can be obtained by using a mask having holes corresponding to the pattern, depositing the pattern in the holes, and removing the mask. The mask can be, for example, a laser-cut sheet of metal.

[0064] At least one optical element may be made of a thin film stack. The stack may be multiple successive layers of alternating low and high refractive index materials. As a non-limiting example, the low refractive index material may be SiO2 and the high refractive index material may be ZrO2.

[0065] As a non-limiting example, one can use the conventional basic thin film stack of Table 1 below, and then add one or several layers onto this stack according to pattern 10 to obtain the desired phase shift. The layers are listed from top to bottom in the stack.

[0066] [Table 1]

[0067] As detailed below, four simulations are performed considering only the wavelength 550 nm.

[0068] Case 1 This first simulation involves optimizing the thickness of one ZrO2 additive layer to obtain a phase shift of 100° at normal incidence and a 30° peripheral angle. An infinite number of solutions exist. The minimum thickness that represents the target phase shift is calculated. The resulting values ​​are: Resulting ZrO2 additional layer thickness: 80.2 nm, Phase shift at 0°: 102.45°, Phase shift at 30°: 100°.

[0069] Case 2 The objective is to "separate" the phase shift values, with the goal being less than 45° at normal incidence and greater than 90° at a 30° angle of incidence. The resulting values ​​are: Resulting ZrO2 additional layer thickness: 1346.6 nm, Phase shift at 0°: 44.94°, Phase shift at 30°: 93.63°.

[0070] Case 3 The objective is to optimize the thickness of the six additional layers, consisting of alternating ZrO2 and SiO2 layers, to obtain the same phase shift as before. Furthermore, a maximum value of 200 nm and a transmission level higher than 98% are set for each thickness. The resulting values ​​are:

[0071] [Table 2]

[0072] Base stack thickness: 398nm, Total stack thickness including six additional layers: 1273.7 nm (including 875.7 nm for the six additional layers), Phase shift at 0°: 45°, Phase shift at 30°: 95°, Base stack transmittance: 99.58%, Transmittance of the entire stack including six additional layers: 98.57%.

[0073] This example shows the ability of optimization with more variables to provide a better solution, especially in terms of thickness.

[0074] Case 4 In this example, the thicknesses of all layers, including the layers in the base stack, are optimized. As in Case 3, a maximum value of 200 nm is set for each thickness, and a minimum value of 98% is set for the transmittance of both the base stack and the additive stack. The resulting values ​​are: Base stack thickness: 184.45 nm, Total stack thickness including additional layers: 807.95 nm (including 623.5 nm for the additional layers), Phase shift at 0°: 46.3°, Phase shift at 30°: 88.9°, Base stack transmittance: 98% Transmittance of the entire stack including additional layers: 99.1%.

[0075] [Table 3]

[0076] [Table 4]

[0077] The above simulations demonstrate the possibility of designing additional layers to separate the behavior in central and peripheral vision and obtain desired phase shift values.

[0078] It should be noted that all simulations were performed by using a conventional stack of successive layers of ZrO2 and SiO2 without any modification to the stack architecture. A more carefully designed stack architecture could provide even better results.

[0079] In addition, pattern parameters such as layer thickness and distribution of optical elements, their sizes, etc. can be simultaneously optimized.

[0080] Also, only the wavelength value of 550 nm was considered. Polychromatic analysis may provide more relevant results.

[0081] As an alternative to a thin film stack, the at least one optical element may be made of a layer having a predetermined thickness that is deposited on the hard coat of the ophthalmic lens, which layer may be deposited on the hard coat by an inkjet process.

[0082] Table 2 below shows a non-limiting example of a stack of SiO, SnO, and ZrO layers deposited on a hard coat with a thickness of 3000 nm and a refractive index approximately equal to 1.6. The layers are listed from top to bottom in the stack.

[0083] [Table 5]

[0084] The thickness of the substrate can be optimized in the area of ​​the optical element to reach the desired phase shift for three wavelengths: 450 nm, 550 nm and 650 nm. The resulting substrate thickness is 5008.4 nm.

[0085] The advantage of this approach is that the performance of the stack (color saturation, reflectance, etc.) is not compromised and can be designed independently.

[0086] In another embodiment, instead of depositing a layer on a hard coat, the ophthalmic lens may be obtained from a semi-finished lens, and at least one optical element may be disposed on or within the semi-finished lens.

[0087] In another embodiment, the ophthalmic lens may be obtained from a finished lens and the at least one optical element may be disposed on or within the finished lens.

[0088] In certain embodiments, the at least one pattern may be included in a pre-fabricated adhesive film, in which case the thickness and refractive index of the adhesive material will have to be considered.

[0089] Ophthalmic lenses according to the present disclosure can also be obtained by additive manufacturing such as polymer jetting, i.e., droplet deposition, or SLA, i.e., layer-by-layer construction. Such techniques are well suited to providing microstructures of constant thickness.

[0090] In one embodiment, the portion of the ophthalmic lens comprising the at least one pattern of the at least one optical element and the remaining portion of the ophthalmic lens have the same or similar reflectance for wavelengths in the visible range, i.e., in the range of 380 nm to 780 nm, preferably 400 nm to 700 nm, more preferably 400 nm to 650 nm. This is particularly advantageous for the wearer, as it makes it possible to leave the general aesthetic aspects of the lens unchanged.

[0091] It is considered that AR2 is the anti-reflective coating corresponding to the portion of the ophthalmic lens that includes at least one pattern of at least one optical element, and AR1 is the anti-reflective coating corresponding to the remaining portion of the ophthalmic lens.

[0092] Let ΔE represent the relative difference in reflected color between AR1 and AR2.

number

[0093] As used herein, Rv refers to the optical reflectance as defined in the ISO 13666:1998 standard and measured in accordance with ISO 8980-4, i.e., the weighted average spectral reflectance across the visible spectrum from 380 to 780 nm. Rv can be evaluated at any angle of incidence, although it is usually measured at an angle of incidence less than 17°, typically 15°.

[0094] Rv is described by the following formula:

number

[0095] Let ΔRv denote the relative difference in Rv between AR1 and AR2.

number

[0096] The ΔE and ΔRv values ​​given for Examples 1-13 of AR1 and AR2 below show that ΔE<0.2 and ΔRv<0.15. That is, in Example 1, both AR1 and AR2 are colorless (C*<3.5). Because their reflected color is very weak, the calculated ΔE value is not significant and can be ignored.

[0097] [Table 6]

[0098] [Table 7]

[0099] [Table 8]

[0100] [Table 9]

[0101] [Table 10]

[0102] [Table 11]

[0103]

Table 12

[0104]

Table 13

[0105]

Table 14

[0106]

Table 15

[0107] Table 16

[0108]

Table 17

[0109]

Table 18

[0110]

Table 19

[0111] Table 20

[0112] Table 21

[0113] Table 22

[0114] Table 23

[0115] Table 24

[0116] Table 25

[0117] Table 26

[0118] Table 27

[0119] Table 28

[0120] Table 29

[0121] Table 30

[0122] Table 31

[0123] Table 32

[0124] Table 33

[0125] Table 34

[0126] Table 35

[0127] Table 36

[0128] Table 37

[0129] Table 38

[0130] Table 39

[0131] Table 40

[0132] Table 41

[0133] Table 42

[0134] [Table 43]

[0135] [Table 44]

[0136] Figure 7 illustrates a particular embodiment of a lens incorporating a phase-shifting pattern according to the present invention that is capable of reducing myopia and also providing sun protection. That is, in the particular embodiment of Figure 7 and the accompanying examples in Figures 8-17, the present disclosure integrates both myopia reduction and sun protection functions through a particular lens construction.

[0137] The pattern shown in the particular embodiment of Figure 7 and the ten accompanying examples in Figures 8-17 is a random dot pattern with substantially circular dots. The dot size is approximately 242 μm in diameter.

[0138] The phase shift value may be between 145° and 180°, inclusive, so that, as a non-limiting example, a target phase shift value of 157° can be achieved. Such a phase shift pattern provides adequate contrast reduction.

[0139] The curves in Figures 8-17 show the reflectance values ​​in % as a function of wavelength for ten different examples of absorptive anti-reflection coating or mirror coating pairs.

[0140] In Figures 8 and 9, the pair of coatings are anti-reflective coatings, and in contrast to the 13 examples above, AR1 is the anti-reflective coating corresponding to the portion of the ophthalmic lens that contains the pattern, and AR2 is the anti-reflective coating corresponding to the remainder of the ophthalmic lens.

[0141] In Figures 10 to 17, the coating pairs are mirror coatings.

[0142] A pair of anti-reflective or mirror coatings has similar forward reflection properties (represented by the usual parameter Rv already defined above, h*, the hue defined according to the International Color System CIE L*a*b* at an incidence angle of 15°, and C*, the chroma defined according to the International Color System CIE L*a*b* at an incidence angle of 15°), similar transmittance (definitions well known to those skilled in the art), and a low backward reflectance, i.e., 1% or less, represented by the parameter Rb.

[0143] The definitions of back reflection Rb and forward reflection Rf are shown in the left and right parts of the drawing in Figure 18. The definitions of Rb and Rf are as follows:

[0144] Back reflection Rb is defined for a multilayer interference anti-reflective or mirror coating as the total reflection, which is the interference of all sub-reflected beams from all interfaces (R1-R6 in the non-limiting example on the left side of FIG. 18 with five layers A-E). That is, R1 is the sub-reflected beam from the interface between air and layer A, R2 is the sub-reflected beam from the interface between layer A and layer B, R3 is the sub-reflected beam from the interface between layer B and layer C, R4 is the sub-reflected beam from the interface between layer C and layer D, R5 is the sub-reflected beam from the interface between layer D and layer E, and R6 is the sub-reflected beam from the interface between layer E and the substrate.

[0145] The forward reflection Rf is the total reflection away from the substrate, and the back reflection Rb is the total reflection toward the substrate. Thus, as shown in Figure 18, Rf is the interference of all sub-reflected beams from all interfaces (R1-R6 in the non-limiting example of the right portion of Figure 18 with five layers A-E). That is, R1 is the sub-reflected beam from the interface between the substrate and layer E, R2 is the sub-reflected beam from the interface between layer E and layer D, R3 is the sub-reflected beam from the interface between layer D and layer C, R4 is the sub-reflected beam from the interface between layer C and layer B, R5 is the sub-reflected beam from the interface between layer B and layer A, and R6 is the sub-reflected beam from the interface between layer A and air.

[0146] In the present disclosure, the average forward reflectance Rf is given by equation (1) given above, where R(λ) is replaced by the forward reflectance spectrum Rf(λ), and the average backward reflectance Rb is also given by equation (1), where R(λ) is replaced by the backward reflectance spectrum Rb(λ).

[0147] The absorptive anti-reflective or mirror coating pair can be applied directly onto the clear lens, and for sun protection, the coating can be applied without the need for any tinting step.

[0148] In addition, with regard to sun protection, the pair of anti-reflective coatings or mirror coatings can be designed very flexibly from Class 1 to Class 4, and the sun protection levels of these classes are known to those skilled in the art.

[0149] The table below corresponds to the reflectance curves of Figures 8-17 and indicates the stack materials and thicknesses.

[0150] Figure 8 and the associated table below show an example of a green (h* = 135°) antireflection (hereafter referred to as "AR") stack pair. AR1 is a four-layer stack consisting of one layer of a light-absorbing multilayer material, a mixture of 50% Cr and 50% SiO2. AR2 is achieved by adding four alternating layers of SiO2 and three layers of ZrO2 underneath AR1. The phase shift resulting from these seven additional layers in AR2 is 157°. AR1 and AR2 are designed with very similar forward reflection characteristics (Rv, h*, and C*). Furthermore, AR1 and AR2 have similar transmittance and low back reflection (Rb < 0.6%). On the lens surface, the areas corresponding to the dots in the specific embodiment having the pattern shown in Figure 7 are coated with AR1, and the remaining areas of the lens are coated with AR2.

[0151] [Table 45]

[0152] Figure 9 and the associated table below show an example of a blue (h* = 280°) AR stack pair, also composed of one layer of Marb units. AR2 is also obtained by adding four alternating layers of SiO2 and three layers of ZrO2 below AR1. The corresponding phase shift between AR1 and AR2 is 156°. AR1 and AR2 have very similar forward reflection characteristics, transmittance, and low back reflection (Rb < 0.7%). AR stack pairs can also be designed with other hue angles along with other residual reflection colors.

[0153] [Table 46]

[0154] Phase-shift patterns can also be created using pairs of mirror coatings. Figures 10-13 and the associated tables below show some examples of mirror coating pairs. All of these pairs of mirror coatings are composed of one layer of mirror units. The phase shift between the two mirror coatings, hereafter referred to as "Mirror 1" and "Mirror 2," corresponds to the definition of the random dot pattern in Figure 7. Mirror 1 and Mirror 2 in each pair of stacks are designed with very similar forward reflection characteristics (Rv, h*, and C*). Mirror 1 and Mirror 2 also have similar transmittance and low back reflection (Rb<1%).

[0155] FIG. 10 is an example of a top-add blue asymmetric mirror coating pair.

[0156] [Table 47]

[0157] Mirror 2 can be obtained by adding several layers either on top (top add) or bottom (bottom add) of mirror 1. The forward reflectance of the mirror coating pair can be designed at different levels (e.g., 4% to 15%), the reflected color can be designed at different hue angles, and the transmittance can be flexibly designed from Class 1 to Class 4. The asymmetric feature of the mirror coating (with very low Rb) is beneficial to improve the visual comfort of the wearer.

[0158] FIG. 11 is an example of a pair of bottom-added blue asymmetric mirror coatings.

[0159] [Table 48]

[0160] FIG. 12 shows an example of a top-add gold asymmetric mirror coating pair.

[0161] [Table 49]

[0162] FIG. 13 shows an example of a bottom-added gold asymmetric mirror coating pair.

[0163] [Table 50]

[0164] Instead of the sphere units, metal materials such as Cr, Ag, Au, Al, etc. can be used as the light absorbing layer to design the AR / mirror coating pair.

[0165] FIG. 14 shows a bottom-added blue asymmetric mirror coating pair consisting of one layer of Cr.

[0166] [Table 51]

[0167] An AR coating or mirror coating pair can be composed of two, three, or more absorbing layers. For example, Figure 15 shows a bottom-added blue asymmetric mirror coating pair composed of two absorbing layers. Figures 16 and 17 show two pairs of bottom-added and top-added asymmetric mirror coatings, respectively, composed of three absorbing layers.

[0168] [Table 52]

[0169] [Table 53]

[0170] [Table 54]

[0171] While exemplary ophthalmic lenses have been described in detail herein, those skilled in the art will recognize that various substitutions and modifications may be made thereto without departing from the scope of what is described and defined by the appended claims. [Explanation of symbols]

[0172] 10 patterns 12 Optical Elements

Claims

1. 1. An ophthalmic lens adapted to correct a visual defect and slow the progression of said visual defect in an eye of a wearer, the ophthalmic lens having a substrate, a front surface and a back surface, and including at least one pattern of at least one optical element, wherein a difference between a first wavefront produced by a theoretical lens that solely corrects said visual defect by prescription and a second wavefront produced by said ophthalmic lens forms a piecewise affine surface.

2. The ophthalmic lens of claim 1 , wherein the at least one pattern is disposed on the anterior surface, the posterior surface, and / or the substrate.

3. 3. The ophthalmic lens of claim 1, wherein the at least one optical element generates, on the exit pupil, a first phase shift of the second wavefront relative to the first wavefront that is lower than a first predetermined value at a first angle of incidence of light onto the ophthalmic lens, corresponding to the wearer's central vision, and a second phase shift of the second wavefront relative to the first wavefront that is higher than a second predetermined value at a second angle of incidence of light onto the ophthalmic lens, corresponding to the wearer's peripheral vision.

4. An ophthalmic lens according to any one of claims 1 to 3, wherein the at least one pattern includes at least two optical elements, each of the at least two optical elements generating, on an exit pupil, a first phase shift of the second wavefront relative to the first wavefront that is lower than a first predetermined value at a first angle of incidence of light onto the ophthalmic lens, corresponding to the wearer's central vision, and a second phase shift of the second wavefront relative to the first wavefront that is higher than a second predetermined value at a second angle of incidence of light onto the ophthalmic lens, corresponding to the wearer's peripheral vision.

5. 5. An ophthalmic lens according to claim 3 or 4, wherein the first predetermined value is 45° at an angle of incidence of 0° and the second predetermined value is 90° at an angle of incidence of 30°.

6. An ophthalmic lens according to any one of claims 1 to 5, wherein the at least one pattern is obtained by using a mask having holes corresponding to the pattern, depositing the pattern in the holes, and removing the mask.

7. The ophthalmic lens of claim 6 , wherein the mask is a laser-cut sheet of metal.

8. An ophthalmic lens according to any one of claims 1 to 7, wherein the at least one optical element is made of a thin film stack.

9. 9. The ophthalmic lens of claim 8, wherein the thin film stack is a stack of successive layers of alternating low and high refractive index materials.

10. The low refractive index material is SiO ２ and the high refractive index material is ZrO ２ 10. The ophthalmic lens according to claim 9, wherein:

11. An ophthalmic lens according to any one of claims 1 to 10, wherein the at least one optical element is made of a layer having a predetermined thickness, deposited on a hard coat of the ophthalmic lens.

12. The ophthalmic lens of claim 11 , wherein the layer is deposited on the hard coat by an inkjet process.

13. An ophthalmic lens according to any one of claims 1 to 10, obtained from a semi-finished lens and wherein said at least one optical element is arranged on or within said semi-finished lens.

14. An ophthalmic lens according to any one of claims 1 to 13, wherein the at least one pattern is comprised in an adhesive film.

15. 15. An ophthalmic lens according to any one of claims 1 to 14, wherein the part of the ophthalmic lens comprising the at least one pattern of the at least one optical element and the remaining part of the ophthalmic lens have the same or similar reflectivity for wavelengths in the range of 380nm to 780nm, preferably 400nm to 700nm, more preferably 400nm to 650nm.

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