Ophthalmic lens adapted to correct visual impairment and slow progression thereof

Abstract

The ophthalmic lens is adapted to correct visual impairment and slow the progression of visual impairment in the eye of the wearer. An ophthalmic lens has a substrate, an anterior surface, and a posterior surface. The ophthalmic lens comprises at least one pattern (10) of at least one optical element (12), forming a segmented affine surface from the difference between a first wavefront produced by a theoretical lens that corrects visual impairment solely by a prescription and a second wavefront produced by the ophthalmic lens.

Description

Technical Field

[0001] The present disclosure relates to an ophthalmic lens adapted to correct and slow the progression of vision impairment. Background Art

[0002] In some cases, visual impairment is defined as follows: The eye does not focus objects on the retina. For example, in the case of myopia, the eye focuses distant objects in front of its retina. Myopia is usually corrected using concave lenses. Hyperopia is usually corrected using convex lenses.

[0003] For simplicity, by way of non-limiting example, in the following, only the example of myopia will be considered. However, the present disclosure is also applicable to other kinds of visual impairment.

[0004] It is currently possible to mitigate myopia, rather than just correct it, by providing ophthalmic lenses comprising predefined microstructures, such as lenslets.

[0005] For example, document WO-A-2019 / 166657 discloses a lens having such small lenses which compensate for some of the oblique astigmatism so that for an off-axis angle of 30° the small lenses provide point focus.

[0006] Myopia control solutions based on lenslets have proven their effectiveness in clinical trials. However, they have two major drawbacks. First, they are difficult to manufacture and measure. Second, they have a significant impact on central visual acuity.

[0007] Therefore, there is a need for ophthalmic lenses that provide myopia control, are easy to manufacture and do not significantly affect central vision. Summary of the invention

[0008] The purpose of the present disclosure is to overcome the above-mentioned disadvantages of the prior art.

[0009] To this end, the present disclosure provides an ophthalmic lens adapted to correct visual impairment and slow down the progression of visual impairment in an eye of a wearer, the ophthalmic lens having a substrate, a front surface and a back surface, wherein the ophthalmic lens includes at least one pattern of at least one optical element, and a segmented affine surface is formed by the difference between a first wavefront generated by a theoretical lens that corrects the visual impairment only by prescription and a second wavefront generated by the ophthalmic lens.

[0010] Due to the piecewise affine surface, the optical element provides a constant phase shift of the light and, therefore, their combined effect provides a contrast-reduced image at the retinal level. This phase shift brings about myopia control due to the contrast reduction caused by diffraction. The light will travel different distances in the optical element depending on the angle of incidence, resulting in different phase shifts and, therefore, different contrast behavior. This makes it possible to reduce the contrast of the peripheral vision for myopia control while maintaining the central visual acuity as much as possible.

[0011] The present disclosure has many advantages. Such an ophthalmic lens can be manufactured using a simple manufacturing process. Furthermore, since such an ophthalmic lens achieves different optical behaviors depending on the angle of incidence, central vision is less affected than in prior art myopia control lenses. Furthermore, such an ophthalmic lens is compatible with an anti-reflective coating step or even a hard coating, so no special inserts or molds are required to provide the above-mentioned pattern.

[0012] In an embodiment, at least one pattern is located on the front surface and / or on the back surface and / or on the substrate.

[0013] In an embodiment, at least one optical element produces a first phase shift of the second wavefront relative to the first wavefront and a second phase shift of the second wavefront relative to the first wavefront at the exit pupil, the first phase shift being lower than a first predetermined value when light is incident on the ophthalmic lens at a first incident angle, the first incident angle corresponding to the central vision of the wearer, and the second phase shift being higher than a second predetermined value when light is incident on the ophthalmic lens at a second incident angle, the second incident angle corresponding to the peripheral vision of the wearer.

[0014] In an embodiment, at least one pattern comprises at least two optical elements, each of the at least two optical elements producing a first phase shift of the second wavefront relative to the first wavefront and a second phase shift of the second wavefront relative to the first wavefront on the exit pupil, the first phase shift being lower than a first predetermined value when light is incident on the ophthalmic lens at a first incident angle, the first incident angle corresponding to the central vision of the wearer, and the second phase shift being higher than a second predetermined value when light is incident on the ophthalmic lens at a second incident angle, the second incident angle corresponding to the peripheral vision of the wearer.

[0015] In an embodiment, the first predetermined value is 45° at an incident angle of 0°, and the second predetermined value is 90° at an incident angle of 30°.

[0016] In an embodiment, 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.

[0017] In an embodiment, the mask is a laser cut metal sheet.

[0018] In an embodiment, at least one optical element is made of a thin film stack.

[0019] In an embodiment, the thin film stack is a stack of alternating successive layers of low refractive index material and high refractive index material.

[0020] In an embodiment, the low refractive index material is SiO2 and the high refractive index material is ZrO2.

[0021] In an embodiment, at least one optical element is made of a layer with a predetermined thickness deposited on a hard coating of an ophthalmic lens.

[0022] In an embodiment, the layer is deposited on the hardcoat layer by an inkjet process.

[0023] In an embodiment, the ophthalmic lens is obtained from a semi-finished lens and the at least one optical element is arranged on or in the semi-finished lens.

[0024] In an embodiment, the ophthalmic lens is obtained from a finished lens and the at least one optical element is arranged on or in the finished lens.

[0025] In an embodiment, at least one pattern is comprised in the adhesive film.

[0026] In an embodiment, the portion of the ophthalmic lens comprising at least one pattern of at least one optical element and the rest of the ophthalmic lens have the same reflectivity or similar reflectivity for wavelengths ranging from 380nm to 780nm, preferably from 400nm to 700nm, more preferably from 400nm to 650nm.

[0027] In an embodiment, the visual impairment is myopia. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] For a more complete understanding of the description provided herein and the advantages thereof, 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.

[0029] Figure 1 is a first non-limiting example of an optical element pattern according to the present disclosure.

[0030] Figure 2 and Figure 3 Is to show and Figure 1 The pattern corresponds to a graph of the cost function.

[0031] Figure 4 is a second non-limiting example of an optical element pattern according to the present disclosure.

[0032] Figure 5 Is to show and Figure 4The pattern corresponds to a graph of the cost function.

[0033] Figure 6 is a third non-limiting example of an optical element pattern according to the present disclosure.

[0034] Figure 7 A specific embodiment of a lens comprising a phase shifting pattern according to the present invention is shown which makes it possible to control myopia and additionally provide sun protection.

[0035] Figures 8 to 17 Shown with Figure 7 Non-limiting examples of coatings corresponding to specific embodiments of the present invention.

[0036] Fig.18 is a diagram showing definitions of parameters used in the present disclosure. DETAILED DESCRIPTION

[0037] In the description below, although making and using different embodiments are discussed in detail below, it should be understood that, as described herein, many inventive concepts that can be embodied in various contexts are provided. The embodiments discussed herein are merely representative and do not limit the scope of the present disclosure. It is also apparent to those skilled in the art that all technical features defined with respect to the method can be transposed to the device alone or in combination, and conversely, all technical features with respect to the device can be transposed to the method alone or in combination, and the technical features of different embodiments can be exchanged or combined with the features of other embodiments.

[0038] 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 "including") are open-ended linking verbs. They are used to specify the presence of stated features, integers, steps or components or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps or components or groups thereof. Therefore, a method or step in a method that "comprises", "has", "contains" or "includes" one or more steps or elements has the one or more steps or elements, but is not limited to only the one or more steps or elements.

[0039] An ophthalmic lens according to the present disclosure is adapted to correct a visual impairment and slow the progression of a visual impairment in a wearer's eye.

[0040] By way of non-limiting example, the visual impairment may be myopia. However, as mentioned above, the present disclosure is also applicable to other kinds of visual impairment.

[0041] The ophthalmic lens has a substrate, a front surface and a back surface. In addition, the ophthalmic lens includes one or more patterns of one or more optical elements. These optical elements are such that the difference between a first wavefront generated by a theoretical lens that corrects the visual impairment only by prescription and a second wavefront generated by the ophthalmic lens forms a piecewise affine surface.

[0042] In certain embodiments, the optical element may produce a constant phase shift.U0(ξ,η) is defined as the phase function produced by a typical single vision lens, where ξ and η are the coordinates of the phase function in the plane of the exit pupil.

[0043] If the optical element produces a constant phase shift Φ0 for a given wavelength (e.g. 550 nm), the additional phase factor is Then, the complete phase function will be defined as follows:

[0044]

[0045] In the formula, the base is the carrier, that is, the surface without optical elements.

[0046] In certain embodiments, an attempt may be made to calculate a constant phase shift such that the properties of the ophthalmic lens approximate the properties of a well-known control lens. For example, if the target myopic control lens has an optical element pattern with a lower add power of P, the phase factor introduced by the optical element will be, in a second order approximation:

[0047]

[0048] Where k = 2πdn / λ is the wave number, dn is the refractive index change due to the optical element, and λ is the wavelength.

[0049] The complete phase function will be defined as follows:

[0050]

[0051] Where U0 is the phase function due to the ophthalmic lens when no optical elements are included.

[0052] Now consider an optical element that introduces a constant phase shift Φ0 for a given wavelength (eg 550 nm).

[0053]

[0054] Φ0 is found so that 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 the lower add power P. The PSF is obtained by Fourier transform of the phase function defined above.

[0055] This is equivalent to minimizing the cost function, that is, determining:

[0056]

[0057] In the formula, (x i ,y i ) is a sampling of the image surface.

[0058] Figure 1 A non-limiting example of a pattern 10 of optical elements 12 according to the present disclosure is shown. The optical elements 12 are contiguous circles, and the pattern 10 has a circular shape in the center of which there are no optical elements in a hexagonal area H. The dark spot below the hexagonal area H represents the intersection of the light rays with the surface when the gaze direction is reduced by 15° in central vision for a pupil size of 4 mm.

[0059] Figure 2 A graph of the corresponding cost function is shown, which reveals two minima symmetrical about 180°. The abscissa axis is the phase shift Φ0 in degrees. The pupil size is 4 mm.

[0060] The PSF is the same for Φ0=100° and Φ0=260°.

[0061] In another embodiment, in order to reproduce the contrast modulation characteristics of the lenslet array, the modulation transfer function MTF may be targeted instead of the PSF in the cost function.

[0062] In this embodiment, the goal is to minimize:

[0063]

[0064] Figure 3 Shows Figure 1 Graph of the corresponding cost function in the pattern example.

[0065] In this embodiment, in contrast to the PSF target approach, the cost function exhibits a much larger region of acceptable phase shift values.

[0066] Figure 4Another non-limiting example of a pattern 10 of optical elements 12 according to the present disclosure is shown. The optical elements 12 are circles arranged on a plurality of concentric circles. There are no optical elements in the circular region C in the center of the pattern 10. The dark spot below the circular region C represents the intersection of the light rays with the surface when the gaze direction is reduced by 15° in central vision for a pupil size of 4 mm.

[0067] Figure 5 A graph of the corresponding cost function is shown. The pupil size is 4 mm. Figure 5 The cost function is not as good as Figure 3 The cost function is stable.

[0068] The pattern 10 may have a non-circular profile. For example, it may be a rectangular grid, defined by the following parameters:

[0069] s x : Horizontal step length

[0070] s y : Vertical step length

[0071] w x : Horizontal bandwidth

[0072] w y : Vertical bandwidth

[0073] c x : Horizontal offset

[0074] c y : Vertical offset

[0075] The phase function of this rectangular grid can be defined as follows:

[0076]

[0077] Where mod is the modular operator used to implement the periodicity of the pattern.

[0078] Figure 6 An example of a rectangular grid with the following values ​​is shown:

[0079] s x =s y =1.5mm

[0080] w x =w y =1mm

[0081] c x =c y =0.5mm

[0082] Φ0=100°

[0083] Pupil size is 4mm.

[0084] The incident angle used for phase shift calculation can take into account the wearing conditions of the ophthalmic lens, such as the lens's anteversion and wrap angles, eye-lens distance, fitting cross position, and base curve. This information can be used to generate a set of normal and oblique incident angles corresponding to central and peripheral vision, respectively.

[0085] By way of non-limiting example, the optical element may be a microstructure, such as a lenslet. The optical element may have various shapes, such as a ring, or a circle, or a rectangular shape, or a hexagonal shape, or an elliptical shape, or a freeform surface, or a NURBS (Non-Uniform Rational B-Spline Surface). This list of examples is not limiting.

[0086] At least one pattern may be located on the front surface and / or the back surface and / or on the substrate.

[0087] At least one optical element can produce the following at the exit pupil (placed directly at the output of the lens, i.e. at the air-lens interface):

[0088] a first phase shift of the second wavefront relative to the first wavefront, the first phase shift being lower than a first predetermined value (e.g. 45°) when light impinges on the ophthalmic lens at a first angle of incidence, the first angle of incidence corresponding to the central vision of the wearer and being, for example, 0°; and

[0089] The second phase shift of the second wavefront relative to the first wavefront is higher than a second predetermined value (eg 90°) when light impinges on the ophthalmic lens at a second incident angle corresponding to the wearer's peripheral vision and is, for example, 30°.

[0090] The first phase shift value and the second phase shift value should be evaluated in the interval [0,180°]. To this end, first, the phase shift should be introduced into the interval [0,360°] by adding multiples of 360°. Then, if the phase shift is between 0 and 180°, no addition step is taken. Otherwise, a symmetrical value relative to 180° is selected.

[0091] In a specific embodiment where at least one pattern comprises at least two optical elements, each of the two optical elements may produce the following at the exit pupil (placed directly at the output of the lens, i.e. at the air-lens interface):

[0092] a first phase shift of the second wavefront relative to the first wavefront, the first phase shift being lower than a first predetermined value (e.g. 45°) when light impinges on the ophthalmic lens at a first angle of incidence, the first angle of incidence corresponding to the central vision of the wearer and being, for example, 0°; and

[0093] The second phase shift of the second wavefront relative to the first wavefront is higher than a second predetermined value (eg 90°) when light impinges on the ophthalmic lens at a second incident angle corresponding to the wearer's peripheral vision and is, for example, 30°.

[0094] Here, too, the first phase shift value and the second phase shift value are considered in the interval [0, 180°] by following the previously defined procedure.

[0095] In other words, a sufficiently low offset may be provided at normal incidence to maintain visual acuity in central vision, and a sufficiently high offset may be provided at oblique incidence to reduce contrast in peripheral vision.

[0096] At least one pattern can be obtained by using a mask having holes corresponding to the pattern, depositing the pattern in these holes and removing the mask.For example, the mask can be a laser cut metal sheet.

[0097] At least one optical element may be made of a thin film stack. The stack may be a plurality of successive layers of alternating low refractive index materials and high refractive index materials. By way of non-limiting example, the low refractive index material may be SiO2 and the high refractive index material may be ZrO2.

[0098] As a non-limiting example, the conventional base film stack of Table 1 below can be used and then one or several layers are added to this stack in order to obtain the desired phase shift according to pattern 10. The layers are listed from top to bottom of the stack.

[0099] Layer Material Layer thickness <![CDATA[SiO2]]> 84.8nm <![CDATA[ZrO2]]> 119.2nm <![CDATA[SiO2]]> 2.8nm <![CDATA[ZrO2]]> 142.2nm <![CDATA[SiO2]]> 32.7nm <![CDATA[ZrO2]]> 16.3nm

[0100] Table 1

[0101] As described below, four simulations were performed, considering only the 550 nm wavelength.

[0102] Case 1

[0103] This first simulation consists in optimizing the thickness of a ZrO2 additive layer to obtain a 100° phase shift at normal incidence and at a 30° ambient angle. There are an infinite number of solutions. The minimum thickness is calculated with respect to the target phase shift. Here are the values ​​obtained:

[0104] Resulting thickness of ZrO2 added layer: 80.2nm

[0105] Phase shift at 0°: 102.45°

[0106] Phase shift at 30°: 100°

[0107] Case 2

[0108] The goal is to "separate" the phase shift values ​​where the target is below 45° at normal incidence and above 90° at 30° incidence. Here are the resulting values:

[0109] Resulting thickness of ZrO2 added layer: 1346.6nm

[0110] Phase shift at 0°: 44.94°

[0111] Phase shift at 30°: 93.63°

[0112] Case 3

[0113] The goal was to optimize the thickness of the six added layers consisting of alternating ZrO2 and SiO2 layers to obtain the same phase shift as before. Further, a maximum value of 200nm was set for each thickness, as well as a transmittance level above 98%. Here are the values ​​obtained:

[0114] Thickness of added layers listed from top to bottom of the stack:

[0115] <![CDATA[SiO2]]> 142.3nm <![CDATA[ZrO2]]> 200nm <![CDATA[SiO2]]> 74.5nm <![CDATA[ZrO2]]> 150.7nm <![CDATA[SiO2]]> 121.9nm <![CDATA[ZrO2]]> 186.3nm

[0116] Thickness of base stack: 398nm

[0117] Thickness of the total stack including six added layers: 1273.7 nm including 875.7 nm for the six added layers

[0118] Phase shift at 0°: 45°

[0119] Phase shift at 30°: 95°

[0120] Transmittance of base stack: 99.58%

[0121] Transmittance of the total stack including six added layers: 98.57%

[0122] This example shows the ability of optimization to provide better solutions with more variables, especially in terms of thickness.

[0123] Case 4

[0124] In this example, the thickness of all layers was optimized, including the thickness of the base stack. As in Case 3, a maximum value of 200nm was set for each thickness, and a minimum value of 98% for the transmittance of both the base stack and the additive stack. Here are the resulting values:

[0125] Thickness of the base stack: 184.45nm

[0126] Thickness of total stack including added layers: 807.95 nm, including 623.5 nm for the added layers

[0127] Phase shift at 0°: 46.3°

[0128] Phase shift at 30°: 88.9°

[0129] Transmittance of base stack: 98%

[0130] Transmittance of the total stack including added layers: 99.1%

[0131] The composition of the base stack from top to bottom:

[0132]

[0133]

[0134] Add stacking from top to bottom composition:

[0135] Layer Material thickness <![CDATA[SiO2]]> 121.8nm <![CDATA[ZrO2]]> 67.9nm <![CDATA[SiO2]]> 110.4nm <![CDATA[ZrO2]]> 78.1nm <![CDATA[SiO2]]> 186nm <![CDATA[ZrO2]]> 59.3nm

[0136] The above simulations show the possibility of designing additional layers to obtain desired phase shift values, thereby separating the behavior in central vision from the behavior in peripheral vision.

[0137] It can be noted that all simulations were performed using a conventional stack of sequential layers of ZrO2 and SiO2 without refining the stack architecture. More aggressive results can be obtained with a more carefully designed stack architecture.

[0138] Additionally, both the layer thickness and pattern parameters, such as the distribution of the optical elements, their size, etc., can be optimized simultaneously.

[0139] Furthermore, only wavelength values ​​up to 550 nm were considered. Polychromatic analysis may give more relevant results.

[0140] As an alternative to a thin film stack, at least one optical element may be made of a layer with a predetermined thickness deposited on a hard coating of the ophthalmic lens. The layer may be deposited on the hard coating by an inkjet process.

[0141] Table 2 below gives a non-limiting example of a layer stack of SiO2, SnO2 and ZrO2 deposited on a hard coating having a thickness of 3000 nm and a refractive index approximately equal to 1.6. The layers are listed from top to bottom of the stack.

[0142]

[0143]

[0144] Table 2

[0145] The thickness of the substrate can be optimized in the region of the optical element to achieve the desired phase shift for three wavelengths, namely 450 nm, 550 nm and 650 nm. The obtained thickness of the substrate is 5008.4 nm.

[0146] The advantage of this approach is that the properties of the stack (chromaticity, reflectance, etc.) are not degraded and the stack can be designed independently.

[0147] In another embodiment, instead of depositing multiple layers on the hard coating, the ophthalmic lens may be obtained from a semi-finished lens, and at least one optical element may be arranged on or in the semi-finished lens.

[0148] 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 in the finished lens.

[0149] In certain embodiments, at least one pattern may be included in a pre-made adhesive film. In this case, the thickness and refractive index of the adhesive material will have to be considered.

[0150] The ophthalmic lenses according to the present disclosure may also be obtained by additive manufacturing, such as polymer jetting (ie droplet deposition) or SLA (ie layer-by-layer build-up). Such techniques are well suited to providing microstructures of constant thickness.

[0151] In an embodiment, the portion of the ophthalmic lens comprising at least one pattern of at least one optical element and the rest of the ophthalmic lens have the same reflectivity or similar reflectivity in the visible range (i.e. for wavelengths ranging from 380 nm to 780 nm, preferably from 400 nm to 700 nm, more preferably from 400 nm to 650 nm). This is particularly advantageous for the wearer, as it makes it possible not to change the overall aesthetic aspects of the lens.

[0152] Consider that AR2 is the anti-reflective coating corresponding to the portion of the ophthalmic lens comprising 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.

[0153] ΔE is indicated as the relative difference in reflected color between AR1 and AR2.

[0154]

[0155] Wherein, L1, L2, a1, a2, b1, b2, C1, and C2 are the theoretical values ​​of L*, a*, b*, and C* of AR1 and AR2, respectively, according to the international colorimetric CIE L*a*b*, for an incident angle of 15°, considering the standard illuminant D65.

[0156] Rv is indicated as the average light reflectance defined in ISO 13666:1998 standard and measured according to ISO 8980-4, i.e. this is the weighted spectral reflectance average over the entire visible spectrum between 380nm and 780nm. Rv is usually measured for an angle of incidence of less than 17°, typically 15°, but can be evaluated for any angle of incidence.

[0157] Rv is described by the following equation:

[0158]

[0159] Where λ indicates the wavelength, R(λ) is the reflectance at wavelength λ, V(λ) is the eye sensitivity function in CIE 1931, and D 65 (λ) is a daylight illuminant defined in the standard CIES005 / E-1998.

[0160] ΔRv is indicated as the relative difference in Rv between AR1 and AR2.

[0161]

[0162] Where Rv1 and Rv2 are the average light reflectances of AR1 and AR2, respectively.

[0163] The values ​​of ΔE and ΔRv given for Examples 1 to 13 below for AR1 and AR2 show that ΔE < 0.2 and ΔRv < 0.15. That is, for Example 1, both AR1 and AR2 are achromatic (with C* < 3.5). Their reflected colors are very weak, so that the calculated value of ΔE is not critical and can be ignored.

[0164] Example 1:

[0165] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 82.71 <![CDATA[ZrO2]]> 135.84 <![CDATA[SiO2]]> 29.45 <![CDATA[ZrO2]]> 16.89

[0166]

[0167]

[0168]

[0169] Example 2:

[0170] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 114.8 <![CDATA[SnO2]]> 6.5 <![CDATA[ZrO2]]> 59.4 <![CDATA[SiO2]]> 33.7 <![CDATA[ZrO2]]> 40.6

[0171]

[0172]

[0173] Example 3:

[0174]

[0175]

[0176]

[0177] Example 4:

[0178] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 78.09 <![CDATA[SnO2]]> 6.5 <![CDATA[ZrO2]]> 94.99 <![CDATA[SiO2]]> 20.86 <![CDATA[ZrO2]]> 21.85

[0179]

[0180]

[0181] Example 5:

[0182]

[0183]

[0184]

[0185]

[0186] Example 6:

[0187] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 78.09 <![CDATA[SnO2]]> 6.5 <![CDATA[ZrO2]]> 94.99 <![CDATA[SiO2]]> 20.86 <![CDATA[ZrO2]]> 21.85

[0188]

[0189]

[0190] Example 7:

[0191]

[0192]

[0193]

[0194]

[0195] Example 8:

[0196] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 66.11 ITO 6.5 <![CDATA[ZrO2]]> 107.81

[0197]

[0198]

[0199] Example 9:

[0200] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 66.11 ITO 6.5 <![CDATA[ZrO2]]> 107.81

[0201]

[0202]

[0203] Example 10:

[0204] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 66.11 ITO 6.5 <![CDATA[ZrO2]]> 107.81

[0205]

[0206]

[0207]

[0208] Example 11:

[0209] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 66.11 ITO 6.5 <![CDATA[ZrO2]]> 107.81

[0210]

[0211]

[0212] Example 12:

[0213] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 68.97 <![CDATA[ZrO2]]> 108.07

[0214]

[0215]

[0216] Example 13:

[0217] AR1 stack material AR1 stack thickness (nm) <![CDATA[SiO2]]> 114.8 <![CDATA[SnO2]]> 6.5 <![CDATA[ZrO2]]> 59.4 <![CDATA[SiO2]]> 33.7 <![CDATA[ZrO2]]> 40.6

[0218]

[0219]

[0220] Figure 7 A specific embodiment of a lens comprising a phase shifting pattern according to the present invention is shown which makes it possible to control myopia and additionally provide sun protection. Figure 7 Specific embodiments and Figures 8 to 17 In the ten accompanying examples, the present disclosure integrates both myopia control function and sun protection function through a specific lens structure.

[0221] exist Figure 7 Specific embodiments and Figures 8 to 17 The pattern shown in the ten accompanying examples is a random dot pattern with substantially circular dots. The diameter of the dot size is about 242 μm.

[0222] The value of the phase shift may be comprised between 145° (inclusive) and 180° (inclusive), such that, by way of non-limiting example, a target phase shift value of 157° may be achieved. Such a phase shift pattern results in an appropriate contrast reduction.

[0223] Figures 8 to 17 The curves show the reflectivity values ​​(in %) as a function of the wavelength (in nm) for ten different examples of absorptive anti-reflective coating pairs or mirror coating pairs.

[0224] exist Figure 8 and Fig. 9 , the coating pair is an anti-reflective coating, wherein, contrary to the thirteen examples given above, AR1 is an anti-reflective coating corresponding to the portion of the ophthalmic lens comprising the pattern, and AR2 is an anti-reflective coating corresponding to the remaining portion of the ophthalmic lens.

[0225] exist Figures 10 to 17 In the embodiment, the coating pair is a mirror coating.

[0226] The anti-reflective coating pair or the mirror coating pair has similar forward reflection characteristics (represented by the usual parameters Rv (already defined above), h* (hue defined according to the international colorimetric CIE L*a*b* for an angle of incidence of 15°) and C* (chromaticity defined according to the international colorimetric CIE L*a*b* for an angle of incidence of 15°)), similar transmittance (whose definition is also well known to the skilled person) and low back reflectivity (i.e., less than or equal to 1%) represented by the parameter Rb.

[0227] Fig.18 The definition of the back reflection Rb and the definition of the forward reflection Rf are shown in the left part of the figure and the right part of the figure respectively. The definitions of Rb and Rf are as follows.

[0228] The retroreflection Rb is defined for a multilayer interference antireflection or mirror coating and is the total reflection of all sub-reflected beams (in Fig.18 In a non-limiting example with five layers A to E on the left part of the figure, there are interferences (R1 to R6): that is, R1 is a sub-reflected beam from the interface between air and layer A, R2 is a sub-reflected beam from the interface between layer A and layer B, R3 is a sub-reflected beam from the interface between layer B and layer C, R4 is a sub-reflected beam from the interface between layer C and layer D, R5 is a sub-reflected beam from the interface between layer D and layer E, and R6 is a sub-reflected beam from the interface between layer E and the substrate.

[0229] The forward reflection Rf is the total reflection away from the substrate, while the backward reflection Rb is the total reflection toward the substrate. Fig.18 As shown, Rf is the total number of sub-reflected beams from all interfaces (in Fig.18 The interference of the light beams R1 to R6 in a non-limiting example having five layers A to E on the right part thereof is as follows: that is, R1 is a sub-reflected light beam from the interface between the substrate and layer E, R2 is a sub-reflected light beam from the interface between layer E and layer D, R3 is a sub-reflected light beam from the interface between layer D and layer C, R4 is a sub-reflected light beam from the interface between layer C and layer B, R5 is a sub-reflected light beam from the interface between layer B and layer A, and R6 is a sub-reflected light beam from the interface between layer A and air.

[0230] In the present disclosure, the forward average reflection coefficient Rf is obtained by the equation (1) given above, where R(λ) is replaced by the forward reflection spectrum Rf(λ), and the backward average reflection coefficient Rb is also obtained by the equation (1), where R(λ) is replaced by the backward reflection spectrum Rb(λ).

[0231] The absorptive anti-reflective coating pairs or the mirror coating pairs can be applied directly on the clear lenses and, with regard to sun protection, these coatings can be applied without any tinting step.

[0232] Furthermore, with regard to sun protection, the anti-reflection coating pairs or mirror coating pairs can be designed in a rather flexible manner from level 1 to level 4, these sun protection level levels being known to those skilled in the art.

[0233] The following table corresponds to Figures 8 to 17 The reflectivity curve of the stack is given, and the material and thickness of the stack are given.

[0234] Figure 8 and the associated table below show an example pair of green (h*=135°) anti-reflective (hereinafter referred to as "AR") stacks. AR1 is a four-layer stack including a layer of light-absorbing Malbunit material, which is a mixture of 50% Cr+50% SiO2. AR2 is obtained by adding alternating 4 layers of SiO2 and 3 layers of ZrO2 below AR1. The phase shift produced by these 7 additional layers in AR2 is 157°. AR1 and AR2 are designed to have very similar forward reflection characteristics (Rv, h* and C*). In addition, AR1 and AR2 have similar transmittance and low retroreflection (Rb<0.6%). On the lens surface, the same as in the specific embodiment with Figure 7 The areas corresponding to the points of the shown pattern are coated with AR1, and the remaining areas in the lens are coated with AR2.

[0235] and Figure 8 The reflectivity curve corresponds to the table:

[0236]

[0237] Fig. 9 And the associated table below shows an example pair of blue (h*=280°) AR stacks, which also include a layer of Malbunit. AR2 is also obtained by adding alternating 4 layers of SiO2 and 3 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 residual reflection colors at other hue angles.

[0238] and Fig. 9 The reflectivity curve corresponds to the table:

[0239]

[0240] It is also possible to use pairs of mirror coatings to produce phase-shifting patterns. Figures 10 to 13 The associated table below shows some example pairs of mirror coatings. All of these mirror coating pairs include a layer of Malbunit. The phase shift between two mirror coatings (hereinafter referred to as "mirror-1" and "mirror-2") corresponds to Figure 7 The random dot pattern is defined. Mirror-1 and Mirror-2 in each pair of stacks are designed to have very similar forward reflection properties (Rv, h* and C*). Mirror-1 and Mirror-2 also have similar transmittance and low back reflection (Rb < 1%).

[0241] Fig.10 Here is an example of a pair with a blue asymmetric mirror coating added on top.

[0242] and Fig.10 The reflectivity curve corresponds to the table:

[0243]

[0244] Mirror-2 can be obtained by adding more layers on top (top addition) or bottom (bottom addition) of mirror-1. The forward reflectance of the mirror coating pair can be designed at different levels (e.g., 4% to 15%), the reflection color can be designed at different hue angles, and the transmittance can be flexibly designed from level 1 to level 4. The asymmetric characteristics of the mirror coating (with very low Rb) are beneficial for improving the visual comfort of the wearer.

[0245] Fig.11 This is an example of a pair with a blue asymmetric mirror coating added to the bottom.

[0246] and Fig.11 The reflectivity curve corresponds to the table:

[0247]

[0248] Fig.12 This is an example of a pair with a gold asymmetrical mirror coating added to the top. Fig.12 The reflectivity curve corresponds to the table:

[0249]

[0250] Fig.13 This is an example of a pair with a gold asymmetric mirror coating added to the bottom. Fig.13 The reflectivity curve corresponds to the table:

[0251]

[0252]

[0253] Instead of Malbunit, a metal material (such as Cr, Ag, Au, Al, etc.) may also be used as a light absorbing layer to design an AR coating pair / mirror coating pair.

[0254] Fig.14 A bottom-added blue asymmetric mirror coating pair comprising a layer of Cr is shown.

[0255] and Fig.14 The reflectivity curve corresponds to the table:

[0256]

[0257] The AR coating pair or mirror coating pair may also include 2, 3, or more absorption layers. For example, Fig.15 A bottom-added blue asymmetric mirror coating pair comprising two absorbing layers is shown. Fig.16 and Fig.17 Two asymmetric mirror coating pairs including three absorption layers are shown, namely, a bottom-added asymmetric mirror coating pair and a top-added asymmetric mirror coating pair. Fig.15 The reflectivity curve corresponds to the table:

[0258]

[0259] and Fig.16 The reflectivity curve corresponds to the table:

[0260]

[0261] and Fig.17 The reflectivity curve corresponds to the table:

[0262]

[0263] Although representative ophthalmic lenses have been described in detail herein, those skilled in the art will recognize that various substitutions and modifications may be made without departing from the scope described and defined by the appended claims.

Claims

1. An ophthalmic lens adapted to correct a visual impairment and slow the progression of the visual impairment in an eye of a wearer, the ophthalmic lens having a substrate, a front surface and a back surface, wherein: The ophthalmic lens comprises at least one pattern of at least one optical element, a piecewise affine surface formed by the difference between a first wavefront generated by a theoretical lens correcting the visual impairment by prescription alone and a second wavefront generated by the ophthalmic lens.

2. The ophthalmic lens according to claim 1, wherein: The at least one pattern is located on the front surface and / or on the back surface and / or on the substrate.

3. The ophthalmic lens according to claim 1 or 2, wherein: The at least one optical element generates a first phase shift of the second wavefront relative to the first wavefront and a second phase shift of the second wavefront relative to the first wavefront on an exit pupil, wherein the first phase shift is lower than a first predetermined value when light is incident on the ophthalmic lens at a first incident angle, the first incident angle corresponding to the central vision of the wearer, and the second phase shift is higher than a second predetermined value when light is incident on the ophthalmic lens at a second incident angle, the second incident angle corresponding to the peripheral vision of the wearer.

4. The ophthalmic lens according to claim 1, 2 or 3, wherein: The at least one pattern comprises at least two optical elements, each of the at least two optical elements producing a first phase shift of the second wavefront relative to the first wavefront and a second phase shift of the second wavefront relative to the first wavefront on an exit pupil, the first phase shift being lower than a first predetermined value when light is incident on the ophthalmic lens at a first incident angle, the first incident angle corresponding to the central vision of the wearer, and the second phase shift being higher than a second predetermined value when light is incident on the ophthalmic lens at a second incident angle, the second incident angle corresponding to the peripheral vision of the wearer.

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

6. An ophthalmic lens according to any one of the preceding claims, 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 according to claim 6, wherein: The mask is a laser cut metal sheet.

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

9. The ophthalmic lens according to claim 8, wherein: The thin film stack is a stack of alternating successive layers of low refractive index material and high refractive index material.

10. The ophthalmic lens according to claim 9, wherein: The low refractive index material is SiO2, and the high refractive index material is ZrO2.

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

12. The ophthalmic lens according to claim 11, wherein: The layer is deposited on the hard coating layer by an inkjet process.

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

14. An ophthalmic lens according to any one of the preceding claims, wherein: The at least one pattern is contained in the adhesive film.

15. An ophthalmic lens according to any one of the preceding claims, wherein: The portion of the ophthalmic lens comprising the at least one pattern of the at least one optical element and the rest of the ophthalmic lens have the same reflectivity or similar reflectivity for wavelengths ranging from 380nm to 780nm, preferably from 400nm to 700nm, more preferably from 400nm to 650nm.

Images