CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 63/308,646, filed February 10, 2022, which is incorporated by reference herein in its entirety.

BACKGROUND

Unless otherwise indicated in the present disclosure, the details described in the present disclosure are not prior art to the claims in the present application and are not admitted to be prior art by inclusion in this section.

Current protective ophthalmic devices may be of two types: polarized and nonpolarized. Polarized sunglasses have an anti-glare property but have issues with regard to reading digital displays. In contrast, non-polarized sunglasses may have no readability issues on digital displays but may provide poor anti-glare properties. Anti-reflection structures may be added to the sunglasses, for example, multiple layers of high-refractive index/low-refractive index (high-n/low-n) transparent materials, and light absorber materials or dyes that may be added separately. However, such structures may be complex and expensive to manufacture.

Thus, there is a need for a simpler protective ophthalmic device structure that provides anti-glare properties while providing the user with the ability to clearly view polarized screens or displays.

SUMMARY

Some embodiments include an ophthalmic element comprising a transparent substrate, having a first side and a second side; a transparent, semi-reflective layer disposed on the second side of the transparent substrate; a first transparent layer disposed upon the semi-reflective layer; a light absorber layer disposed upon the first transparent layer; and a second transparent layer disposed onto the light absorber layer. In some embodiments, the light transmittance of the ophthalmic element (eyewear glasses, sunglasses, goggles, and the like) may be tunable by changing the light absorber layer material and thickness. In some embodiments, the light absorber material may comprise a transition metal with a refractive index greater than about 2.0. In some embodiments, the light absorber material may comprise a transition metal with an extinction coefficient of greater than about 1 .0. In some embodiments, the light absorber material may comprise tungsten or molybdenum. In some embodiments, the light absorber layer may have a thickness between about 2 nm and about 20 nm. In some embodiments, the transparent, semi-reflective layer comprises a metal having a refractive index of less than about 1 .5. In some embodiments, the transparent, semi-reflective layer may comprise silver (Ag) or aluminum (Al). In some embodiments, the transparent, semi- reflective layer may have a thickness of between about 2 nm to about 20 nm, for example about 5 nm to about 10 nm. In some embodiments, transparent, semi-reflective layer comprises a buffer layer and a semi-mirror layer, with the buffer layer disposed between the substrate layer and the semi-mirror for enhancing the performance of the transparent, semi-reflective layer. In some of these buffered embodiments, the buffer layer may comprise chromium (Cr), and semi-mirror layer may comprise Ag. In some embodiments, the first transparent layer and second transparent layers material may comprise a lower refractive index material than the light absorber layer. In some embodiments, the light absorber layer material may have a refractive index (n) greater than about 1 .7 at 550 nm wavelength. In some embodiments, the first and second transparent layers may have a refractive index less than 1.7 at 550 nm wavelength. In some embodiments, the transparent, semi-reflective layer may comprise material having a refractive index of less than 1 at 550 nm wavelength. In some embodiments, the first transparent layer may have a thickness between 10 nm and 80 nm. In some embodiments, the second transparent layer thickness ranges from 10 nm and 100 nm. In some embodiments, the first transparent layer and the second transparent layer comprise silicon dioxide.

Some embodiments include a method for making an ophthalmic element. In some examples, the method may comprise providing a lens material, having a first side and a second side, disposing a transparent semi-reflective layer on the second side (eye side) of the lens material, disposing a first-transparent layer upon the semi-reflective layer; disposing a light absorber layer upon the first transparent layer, and disposing a second transparent layer upon the light absorber layer. In other embodiments, the ophthalmic element may further comprise a lithium fluoride (Li F) coating, on one or both sides of the substrate. In some examples, the ophthalmic element having the structures described herein may have a low visible light reflection down to less than 1% from the eye side to eliminate distracting imaging caused by the reflection from the eye side surface of the lens and/or reducing the readability issues associated with viewing a digital screen comprising a polarizing film. In some embodiments, a method for tuning the %T of an optical ophthalmic element may comprise varying the thickness of the light absorbing layer.

Additional features and advantages will be set forth in the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the schematic diagram of the anti-reflection structure for ophthalmic element embodiments described herein.

FIG. 2 is an embodiment of ophthalmic element described herein with the anti-reflection structure coating on the second side (eyes side) of the lens.

FIG. 3 is an embodiment of ophthalmic element described herein the anti-reflection structure on the second side of the lens with layer of LiF on the first side of the lens.

FIG. 4 is an embodiment of ophthalmic element described herein, wherein the antireflection structure is coated on both sides of the lens.

FIG. 5 is the light transmittance and reflectance of an anti-reflection structure with molybdenum (Mo) as the light absorber layer.

FIG. 6 is the light transmittance and reflectance of anti-reflection structures with tungsten (W) as the light absorber layer with various thickness, and the incident light is from the coating side.

FIG. 7 is the light transmittance and reflectance of anti-reflection structures with tungsten as the light absorber layer.

FIG. 8 is the light transmittance and reflectance of anti-reflection structures with tungsten as the light absorber layer, with LiF coated on the other side of the substrate. FIG. 9 is the comparison of the light reflectance of FIG. 3 and FIG. 4.

FIG. 10 is the comparison of the light transmittance of FIG. 3 and FIG. 4.

DETAILED DESCRIPTION

The embodiments herein relate to anti-reflection elements for use in ophthalmic devices. For purposes of promoting an understanding of the present disclosure, reference will now be made to the following embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the described subject matter, and such further applications of the disclosed principles as described herein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.

The term "transparent" as used herein includes a property in which a layered substrate has a minimal amount of light absorption, and may have a transmittance of light of about 80% to about 100%.

The term “broadband” as used herein includes plural wavelength light, e.g., light having a spectrum of about 400 nm to about 750 nm.

The term “ultrathin” as used herein refers to a thickness on the order of nanometers thick (e.g., less than 200 nm thick).

The term of “asymmetric light absorption” means the light absorption for incident light through a first direction of the ophthalmic element is different than the light absorption from the second, or opposite, direction.

The term of “asymmetric light reflection” means the light reflection for ambient light through a first direction of the ophthalmic element is different from the second, or opposite, direction.

Use of the term “may” or “may be” should be construed as shorthand for “is” or “is not” or, alternatively, “does” or “does not” or “will” or “will not,” etc. For example, the statement “the buffer layer may be in direct contact with the substrate” should be interpreted as, for example, “In some embodiments, the buffer layer is in direct contact with the substrate,” or “In some embodiments, the buffer layer is not in direct contact with the substrate.”

The present disclosure generally relates to anti-reflection ophthalmic elements for eyewear applications (e.g., glasses, sunglasses, goggles, and the like) which provide a user or viewer with improved readability of polarized digital screens. A simple four layer structure coating on a base lens material substrate with an interference cancelation design may provide ambient visible light reflectance as low as less than 1% when the incident light is provided from the coating side. The lens material substrate has a first side and a second side, wherein the first side faces the viewing environment (also referred to as the front side, the view side, or the side away from the eyes) and the second side faces the user or viewer (also referred to as the rear side, eye side, or the coating side). In some embodiments, the four layer structure may comprise a semi-reflection and semi- transmission layer (also referred to as a semi-mirror layer) coated directly on the second side of the lens material, followed by a coating sequence of a first transparent layer, a light absorber layer, and a second transparent layer. In some examples, the refractive index and layer thickness may be arranged in such way that interference cancelation may occur for reflective light when the incident light is from the side away from the eyes (the first side). In some examples, the refractive index and layer thickness may be arranged in such way that interference cancelation may occur for reflective light when the incident light is from eye side (the second side). In some embodiments, the semi-mirror layer may have the lowest refractive index, and the light absorber layer may have the highest refractive index, among the four layers. In some embodiments, the anti-reflection ophthalmic elements may be made by coating the four layer structures on both sides of the base lens material substrate to reduce ambient light reflection from both sides. In some examples, the light absorber layer material may be selected together with the design of the four layer structure, to achieve neutral density or broadband visible light transmission properties of the ophthalmic device for a true color view.

The present disclosure generally relates to anti-reflection ophthalmic elements which include materials having one or more optical properties that may provide varying absorption, transmittance, and reflectance. The present disclosure relates to a broadband ophthalmic transmission and reflectance element utilizing ultrathin light absorber layers with a structure exhibiting enhanced broadband anti-reflection. The embodiments of the current disclosure have a simple structure: a semi-mirror layer is coated on the base lens material substrate, with a first transparent layer and a second transparent layer, a light absorbing layer, and/or a reflective layer, which may have a buffer layer and a metal layer sandwiched and/or ordered as described herein. These elements have both the anti-glare and readability (of a polarized display) properties, and may be manufactured with a highspeed reel-to-reel sputtering process for low-coating thickness. In some examples, incident light passes through the second transparent layer into the light absorber layer wherein a portion of the light may pass through the light absorber layer and the first transparent layer and is partially reflected back by the semi-transparent reflective layer. In these embodiments, incident light meets with reflected light having an opposite phase and provides interference cancellation, decreasing the reflected light and enhancing light absorption in the light absorber layer. In some embodiments, the asymmetric broadband light absorption-reflection ophthalmic element may significantly reduce the reflected ambient light from the eye side to minimize ghost images (distracting images caused by the reflection from the eye side surface of the lens) for a clear forward view of an object or a device. Ghost images interfere with the forward facing image the user desires to see, and are produced by the incident light behind (or above, below, or to the side of) the user which may result by the reflection of incident light from the inner surface of the lens. The present disclosure differs from a conventional polarizer concept and conventional multilayer high-refractive index layer/low-refractive index (high-n/low-n) layer structures. In some embodiments, the film coating of the present disclosure may be ultrathin (e.g., nanometer scale), and may comprise a light absorber layer sandwiched between two transparent layers, and a semi- transparent/reflective mirror layer. In some embodiments, the whole thickness of the ophthalmic element coating of the present disclosure may be less than 200 nm, which may be formed by a roll-to-roll sputtering process and high throughput mass production. Some embodiments include the potential for low-cost, flexible, and ultrathin anti-reflection and anti-glare coatings for eyewear without readability issues with regard to a polarized digital display device.

In some embodiments, the broadband asymmetric light absorption-reflection may comprise a semi-transparent and semi-reflective mirror layer contacting, disposed upon, or coated upon the substrate, a first transparent layer, contacting, disposed upon, or coating the semi-mirror layer, a light absorber layer, contacting, disposed upon, or coating the first transparent layer; and a second transparent layer, contacting, disposed upon, or coating the light absorber layer. The refractive index and layer thickness of the semimirror layer, the two transparent layers, and the light absorber layer, are designed such that interference cancelation happens for reflective light when the incident light is from the side of the second transparent layer. The reflectance may be as small as less than about 1 %. It is believed that the incident ambient light from the second transparent layer surface passes through the second transparent layer into the light absorber layer and at least a portion of the light is passing through the light absorber layer and the first transparent layer and partially reflected back by the semi-mirror layer.

An anti-reflection ophthalmic element is depicted in FIG. 1 . In some embodiments, the anti-reflection structure, such as structure 10, may comprise a transparent substrate, such as substrate 12 (i.e. , the lens material); a semi-transparent reflective (or semi-mirror) layer, such as layer 14, a first transparent layer, such as layer 16, a light absorber layer, such as layer 18, and/or a second transparent layer, such as layer 20. Incident light in a direction from the anti-reflection film side is indicated by first arrow 22 and the incident light in a second direction from the substrate (lens material) side is indicated by second arrow 24. In some embodiments, the ophthalmic device may have a low visible light reflection of less than about 5%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, or less than about 1% from the eye side to eliminate distracting ghost images caused by the reflection from the eye side surface of the lens. In some embodiments, the ophthalmic device has reduced issues with respect to the readability of a digital screen comprising a polarizing film.

In some embodiments, the eye side surface of the lens is structurally different from the outward facing surface. For example, many lenses have curved surfaces, such that the eye side is concave, or is shaped like the inside of a curve, and the outside facing side is convex, or is shaped like the outside of a curve.

For the incident light from the anti-reflection rear side indicated by arrow 22, the light may be reflected and/or transmitted at the interface of any of the adjacent layers of the coating layers. The refractive index and layer thickness of the four layers may be arranged in such way that interference cancelation happens for reflective light. The total reflective light from the second transparent layer may be minimized as low as less than 5%, for example less than 1%. In some embodiments, the semi-mirror layer has the lowest refractive index relative to the other layers, and the light absorber layer has the highest refractive index relative to the other layers.

In some embodiments, incident light from the first side of the ophthalmic device may not have the same light cancelation as from the rear side, and may have a high reflectance. In some examples, the reflectance difference (AR %) of the two opposite incident light directions through the designed ophthalmic device may be as high as 40%, leading to a mirror like appearance when it is viewed from the first side.

In some embodiments, the ophthalmic device may comprise a transparent, semi- reflective layer. In some embodiments, the transparent semi-reflective layer may have a first side and a second side. In some embodiments, the semi-reflective layer may partially reflect light and also partially transmit light therethrough. In some embodiments, the semimirror layer may transmit or allow transmission (T%) of between about 20% total transmittance to about 80% total transmittance, about 20-30% and 30-40%, about 40- 50%, about 50-60%, about 60-70%, about 70-80%, or any transmittance in a range bounded by any of these values therethrough. In some embodiments, the semi-reflective layer may reflect (R%) about 50% to about 100%, about 50-60%, about 60-70%, about 70-80%, about 80-90%, about 90-100%, or any reflectance of the light impinging thereupon in a range bounded by any of these values.

In some embodiments, the semi-reflective layer may have a two-layer structure comprising a buffer layer and a mirror layer. In some examples, the buffer layer may be in direct contact with the substrate thereby enhancing film formation and adhesion of the mirror layer. In some embodiments, the buffer layer may be copper (Cu) or chromium (Cr). In some embodiments, the buffer layer may comprise chromium (Cr), and the mirror layer may have a low refractive index (n), for example less than about 1.5. In some embodiments, the mirror layer comprises silver (Ag), having nd in the visible range. In some embodiments, the thickness of the buffer layer may be about 0 nm to about 5 nm, about 0-0.2 nm, about 0.2-0.4 nm, about 0.4-0.6 nm, about 0.6-0.8 nm, about 0.8-1 nm, about 1 -2 nm, about 2-3 nm, about 3-4 nm, about 4-5 nm, or about 0.3 nm, about 0.5 nm, about 0.7 nm, or any thickness in a range bounded by any of these values. In some examples, the mirror layer may be about 2 nm to about 20 nm, about 2-5 nm, about 5-7 nm, about 7-10 nm, about 10-15 nm, about 15-20 nm, or about 7 nm, or any thickness in a range bounded by any of these values. In some embodiments, the total thickness of the anti-reflective layer comprising the buffer layer and the mirror layer is less than about 10 nm, less than about 9 nm, or less than about 8 nm.

In some embodiments, the light absorber layer may have a first side and a second side. In some examples, the light absorber layer may comprise a material having a higher refractive index than the other layers. In some embodiments, the light absorber layer comprises a metal. In some embodiments, the light absorbing material may comprise tungsten (W), nickel (Ni), chromium (Cr), aluminum (Al), manganese (Mn), molybdenum (Mo), or a combination thereof. In some embodiments, the light absorbing material may be a partially oxidized metal. In some embodiments, the partially oxidized metal may be WOx, wherein x is less than 3 (e.g., WO2). In some examples, the light absorber layer may comprise molybdenum (Mo) or tungsten (W), having a refractive index (n) of greater than about 2. In some embodiments, the light absorber layer comprises W, having a refractive index of 3.5 at 550 nm. In some embodiments, the light absorber layer comprises Mo, having a refractive index of 3.8 at 550 nm. In some embodiments, the material of the light absorber layer may have an extinction coefficient (k) of greater than about 1. In some embodiments, the light absorber layer comprises W, having an extinction coefficient of 2.73 at 550 nm. In some embodiments, the light absorber layer comprises Mo, having an extinction coefficient of 4.5 at 550 nm. In some embodiments, a higher extinction coefficient and/or layer thickness may lead to more light absorption and lower light transmittance. The thickness of the light absorber layer may range from about 2 nm to about 20 nm, about 2-4 nm, about 4-6 nm, about 6-7.5 nm, about 7.5-8 nm, about 8-10 nm, about 10-15 nm, about 15-20 nm, or about 4 nm, about 6 nm, about 7.5 nm, about 8 nm, about 10 nm, or any thickness in a range bounded by any of these values. It is believed that a larger difference in the refractive index of the light absorber layer relative to the other layers of the anti-reflection structure provides an anti-reflection property with broadband performance that alternatively could only be realized in tens or hundreds of multilayers of conventional high-n/low-n structures.

Some embodiments of the ophthalmic elements described herein feature the antireflection structure coating on the second or rear side (eyes side) of the substrate (lens), as shown in FIG. 2.

FIG. 2 shows an ophthalmic element assembly, such as assembly 210, comprising an ophthalmic element, such as element 10, which comprises a transparent substrate 12, a transparent, semi-reflective layer 14 contacting, disposed upon and/or coated upon the substrate, a first transparent layer 16 contacting, disposed upon and/or coated upon the semi-mirror layer, a light absorbing layer 18 contacting, disposed upon and/or coated upon the first transparent layer, and a second transparent layer 20 contacting, disposed upon and/or coated upon the light absorbing layer. Assembly 210 also comprises a frame assembly, such as frame assembly 212, and further comprises a first and a second hingeably attached temple assembly, such as temple assemblies 214A and 214B.

In the configuration of layers shown in FIG. 1 and FIG. 2, the ambient light from the rear-side (eyes side) may be significantly reduced to as low as less than 1%. While the front view of the ophthalmic device is like a mirror, the user’s eyes are not visible to an outside observer when the user wears these ophthalmic elements, while the user may see objects clearly with enhanced clarity without the ghost images of objects from the rear side. Other configurations of the layers are also considered. FIG. 3 is an embodiment of an ophthalmic element comprising the four layer antireflection structure on the rear side of the lens (as in FIG. 2) having an additional low refractive index (low-n) coating layer, such as layer 36, on the front side of the lens. In some embodiments, the additional low-n coating layer of the anti-reflection structure may comprise an alkali metal halide, e.g., lithium fluoride (LiF). In some examples, the additional low-n coating layer on the front side of the lens may further reduce the light reflection from the rear side to as low as less than 0.5%. In some cases, the additional low-n coating layer may increase the light transmittance (T%) up to about 5%, and in other examples, it may increase the light transmittance less than 1%. In some embodiments, the additional low-n layer is deposited or coated on both sides of the ophthalmic element. In some examples, the additional low-n coating layer may have a thickness of about 20 nm to about 100 nm, about 20-30 nm, about 30-40 nm, about 40- 50 nm, about 50-60 nm, about 60-70 nm, about 70-80 nm, about 80-90 nm, about 90-100 nm, about 45-50 nm, or about 48 nm, or any thickness in a range bounded by any of these values.

FIG. 4 is an embodiment of an ophthalmic element comprising an anti-reflection structure coating on both sides (front and rear side) of the substrate lens. In some examples of this configuration, the reflection of ambient light from both the front side and the rear side may be minimized. In some embodiments of this structure, the user of the ophthalmic elements clearly sees the front view, and the user’s eyes may be viewed clearly from the front side of the element. In FIGs. 2-4, incident light in a direction from the first side is indicated as line 30 and incident light from the second (eye) side is indicated as line 32.

In some embodiments, the total visible light transmittance (T%) of the antireflection structure may range from about 5% to about 60%, about 5-10%, about 10-20%, about 20-30%, about 30-40%, about 40-50%, about 50-60%, or any T% in a range bounded by any of these values. In some embodiments, the semi-reflective layer may allow light transmission from about 10% to about 80%.

In some embodiments, the first transparent layer and the second transparent layer may comprise a transparent insulating layer. In some embodiments, the first transparent and/or the second transparent layer may comprise an oxide, nitride, or halide. In some embodiments, the light absorber layer comprises a metal, a partially oxidized metal, or a semiconductor. In some examples, the first transparent layer and the second transparent layer may comprise transparent materials with a refractive index lower than the light absorber layer. Any suitable transparent material may be used for the first transparent layer and the second transparent layer. In some embodiments, the transparent materials may be SiC>2, SisN4, AI2O3, AIN, WO3, MoOs, or a combination thereof. In some embodiments, the first transparent layer and the second transparent layer are the same material. In other embodiments, the first transparent layer and the second transparent layer are different materials. In some examples, the first transparent layer and the second transparent layer comprise SiC>2. Other suitable transparent materials for the first transparent layer and the second transparent layer may include, but are not limited to, those shown in Table 1 below.

Table 1

In some embodiments, the first and second transparent layers may have thicknesses be between about 1 nm to about 100 nm. In some examples, the first transparent layer may have a thickness of about 20 nm to about 40 nm, about 20-25 nm, about 25-30 nm, about 30-35 nm, about 35-40 nm, or about 30 nm, or any thickness in a range bounded by any of these values. In some embodiments, the second transparent layer may have a thickness of about 40 nm to about 80 nm, about 40-45 nm, about 45- 50 nm, about 50-55 nm, about 55-60 nm, about 60-65 nm, about 65-70 nm, about 70-75 nm, about 75-80 nm, or about 75 nm, or any thickness in a range bounded by any of these values. In some embodiments, the first and second transparent layers may each have first and second sides.

In some embodiments, the refractive index and layer thickness of the first transparent layer and the second transparent layer may be arranged such that interference cancellation occurs for the incident ambient from the film-side, and the light reflectance (R%) may be reduced to as low as less than 1%. In some embodiments, when the first transparent layer and the second transparent layer have the same or similar refractive index, the layer more proximal to the exterior impinging light and or more distal from the reflective surface, may be thicker in order to provide a layer that has a greater refractive index value, e.g., a greater value of thickness of transparent layer times the thickness of the respective layer. For example, where the first transparent layer and the second transparent layer comprise silicon dioxide, the first transparent layer, that more proximal to the reflective layer and/or distal to the impinging incident light, may be between 15 and 70 nm thick (e.g., 30 nm thick), and the second transparent layer, that more distal to the reflective layer and/or proximal to the impinging incident light may be between 45 and 95 nm thick may be thicker (e.g., 75 nm thick). In some embodiments, the first and second dielectric layers may comprise different dielectric materials, e.g., one having a higher refractive index. In other embodiments, the first and second transparent layers may have the same thickness, but comprise materials having different refractive indices.

In some embodiments, the ophthalmic element comprises a substrate layer. In some embodiments, the substrate layer may have a first and second side. In some embodiments, the substrate layer may comprise a transparent material. In some embodiments, the transparent material may be the same or different from the first transparent layer and/or the second transparent layer. In some embodiments, the substrate layer comprises an ophthalmic lens material. The lenses of the eyeglasses may comprise any suitable conventional lens material (e.g., a variety of glasses or polymers). In some embodiments, the lens material comprises a glass. Any suitable glass may be used as a lens material for the ophthalmic elements described herein. Some non-limiting examples of suitable glasses include silica-based glasses, germanium oxides (glasses based on GeC ), tellurites (glasses based on TeC ), antimonates (glasses based on Sb20s), arsenic oxides (glasses based on AS2O3), titanates (glasses based on TiC ), tantalates (glasses based on Ta2Os) and combinations thereof. In some embodiments, the lens material is a silica-based glass. Some non-limiting examples of suitable silica- based glasses include crown glass and flint glass.

In some embodiments, the lens material may comprise a plastic material. Any suitable plastic may be used in the ophthalmic elements described herein. Some non- limiting examples of suitable plastics include polyalkyl acrylates, polyalkyl methacrylates such as polymethyl methacrylate (e.g., PLEXIGLAS™, LIMACRYL™, R-CAST™, PERSPEX™ PLAZCRYL™ ACRYLEX™ ACRYLITE™, ACRYLPLAST™, ALTUGLAS™, POLYCAST™ and LUCITE™), polycarbonates, resins (e.g., CR39™ or allyl diglycol carbonate), polyurethanes and combinations thereof.

In some embodiments, the ophthalmic elements lens materials used herein may be prescription or corrective lenses for modifying the focal length of the eye to alleviate the effects of nearsightedness (myopia), farsightedness (hyperopia) or astigmatism.

In some embodiments, the ophthalmic elements described herein may be safety eyeglasses made with shatter-resistant plastic lenses to protect the eye from flying debris. In some embodiments, the lens may have a minimum thickness of 1 millimeter at the thinnest point, regardless of the substrate lens material. In other embodiments, the lenses of the safety glasses may also be shaped for correction.

In some embodiments, safety glasses are designed to fit over corrective glasses or sunglasses. They may provide less eye protection than goggles or other forms of eye protection, but their light weight and designs encourages their use. In some embodiments, corrective glasses with plastic lenses may be used in the place of safety glasses.

In some embodiments, the ophthalmic elements described herein may be used as safety glasses for welding, which may be styled like wraparound sunglasses, but with much darker lenses, for use in environments where a full-sized welding helmet is inconvenient or uncomfortable. These are often called “flash goggles” because they provide protection from welding flash.

In certain embodiments, the ophthalmic elements of the present disclosure are sunglasses. In some examples, sunglasses may be made with either prescription or nonprescription lenses that are darkened to provide protection against bright visible and possibly ultraviolet light in addition to the anti-reflection structure of the present disclosure.

In some embodiments, the ophthalmic elements of the current disclosure include eyeglasses with photosensitive lenses, called photochromic lenses, which become darker in the presence of UV light.

In some embodiments, a method for preparing a light absorber element may be described. In some embodiments, the method may comprise providing a substrate. In some embodiments the method may comprise providing a semi-reflective-transmissive layer. In some embodiments, the method may comprise providing a first transparent layer wherein the first transparent layer may comprise a transparent material and in optical communication with the first transparent layer. In some embodiments, the method may comprise providing a light absorbing layer. In some embodiments, the method may comprise providing a second transparent layer. In some embodiments, the aforementioned layers may be disposed atop one another in the aforementioned order or stack. In some embodiments, a method for tuning the light transmittance (% total transmittance through the ophthalmic element) comprises varying the thickness of light absorber layer. In some embodiments, the method may comprise varying the materials of the light absorber layer, as the materials with high extinction coefficient may give a better light absorption with similar thickness.

EMBODIMENTS

Embodiment 1. An ophthalmic element comprising: a transparent substrate, having a first side and a second side; a transparent, semi-reflective layer disposed on the second side of the transparent substrate; a first-transparent layer disposed upon the semi-reflective layer; a light absorber layer disposed upon the first transparent layer; and a second transparent layer disposed onto the light absorber layer.

Embodiment 2. The ophthalmic element of embodiment 1 , wherein the light transmittance of the eyewear glasses is tunable by changing the light absorber layer material and thickness

Embodiment 3. The ophthalmic element of embodiment 1 , wherein the light absorber material comprises a transition metal with a refractive index greater than 2.0.

Embodiment 4. The ophthalmic element of embodiment 1 , wherein the light absorber material comprises a transition metal with an extinction coefficient of greater than 1 .0.

Embodiment 5. The ophthalmic element of embodiment 3, wherein the light absorber material comprises tungsten or molybdenum.

Embodiment 6. The ophthalmic element of embodiment 1 , wherein the light absorber layer has a thickness between 2nm to 20nm. Embodiment 7. The ophthalmic element of embodiment 1 , wherein the transparent, semi-reflective layer comprises a metal having a refractive index of less than 1 .5.

Embodiment 8. The ophthalmic element of embodiment 1 , wherein the transparent, semi-reflective layer comprises silver or Al.

Embodiment 9. The ophthalmic element of embodiment 1 , wherein the transparent, semi-reflective layer has a thickness of between 2 nm to 20nm, preferably 5-10nm.

Embodiment 10. The ophthalmic element of embodiment 1 , further comprising a buffer layer disposed between the transparent, semi-reflective layer and the substrate layer for enhancing the performance of the transparent, semi-reflective layer

Embodiment 11. The ophthalmic element of embodiment 9, wherein the buffer layer comprises Cr, and where in the transparent, semi-reflective layer comprises Ag.

Embodiment 12. The ophthalmic element of embodiment 1 , further comprising a hard coating layer coated on at least one surface of the transparent substrate.

Embodiment 13. The ophthalmic element of embodiment 1 , wherein the hard coating is deposited on the first surface of the transparent substrate to decrease light reflection from the first surface of the lens.

Embodiment 14. The ophthalmic element of embodiment 1 , wherein the hard coating comprises a material having a refractive index of less than 1 .45 at 550nm wavelength.

Embodiment 15. The ophthalmic element of embodiment 1 , wherein the first and second transparent layers material comprise a lower refractive index material than the light absorber layer.

Embodiment 16. The ophthalmic element of embodiment 1 , wherein the light absorber layer material has refractive index n>1 .7 at 550nm wavelength

Embodiment 17. The ophthalmic element of embodiment 1 , wherein the first and second transparent layers have refractive index nd .7 at 550nm wavelength

Embodiment 18. The ophthalmic element of embodiment 1 , wherein the mirror layer material has a refractive index of nd at 550nm wavelength Embodiment 19. The ophthalmic element of embodiment 1 , wherein the first transparent layer has a thickness between 10 nm and 80nm.

Embodiment 20. The ophthalmic element of embodiment 1 , wherein the second transparent layer thickness ranges from 10 nm and 100nm.

Embodiment 21. A method for making ophthalmic element comprising:

Providing a lens material, having a first side and a second side;

Disposing a semi-mirror layer on the second side (rear-side surface (eye side)) of the lens material;

Disposing a first-transparent layer upon the semi-mirror layer;

Disposing a light absorber layer upon the first transparent layer;

Disposing a second transparent layer upon the light absorber layer; wherein the ophthalmic element having the above structure has low visible light reflection down to less than 1% from the eye side to eliminate distracting imaging caused by the reflection from the eye side surface of the lens, without readability issue on digital screen comprising a polarizing film.

Embodiment 22. A method for tuning the T% of optical ophthalmic element comprising varying the thickness of the light absorbing layer.

EXAMPLES

Preparing Asymmetric light absorption-reflection architecture for anti-reflection eyewear glasses without issue of reading digital displays.

It should be appreciated that the following examples are for illustration purposes and are not intended to be construed as limiting the subject matter disclosed in this document to only the embodiments disclosed in these examples.

The examples were prepared as follows:

Glass substrates were loaded onto a home-made sputtering system. The base vacuum was less than 2 x 10' ⁶ torr. First, direct current (DC) sputtering Cr as the buffer layer, followed by DC sputtering Ag as the semi-mirror layer to create the semi-reflective layer. This was followed by the reactive sputtering of SiO2 for the first transparent layer, from a Si sputtering target under a processing gas of argon (Ar) and oxygen (O2), the gases controlled separately by mass flow controllers, the Ar flow rate was 10 Standard Cubic Centimeters per Minute (SCCM), the O2 rate was 2 SCCM, the deposition rate was about 2 A/sec. Next a molybdenum or tungsten (Mo or W) layer was deposited from either a molybdenum (Mo) target or a tungsten (W) target respectively at a deposition rate of about 0.5 A/s. Next, a second transparent layer of silicon dioxide (SiC ) was deposited in a manner similar to the first transparent layer to complete the absorption-reflection (AR) structure fabrication. Examples 2-4 were made in a similar manner, except that the layer thicknesses and materials were varied as described in Table 2 below (the numbers in parentheses represent the thickness of the coating/layer in nm). For example, Ex-2 (Ex- 2A, -2B, -2C, and -2D) was made in a similar manner, except that additional variations were made with different thickness light absorber layers as described in Table 2. For example, Ex-4, the low n-layer (Li F) was thermally evaporated on both sides of the glass substrate (lens) with a deposition rate about 2A/s by Angstrom vacuum deposition chamber at base vacuum of less than 2 x 10' ⁶ torr.

TABLE 2.

Measurement of the light transmittance (T%), reflectance (R%) and absorbance (A%), specular and total reflection, and the viewing-angle dependent light output and color

A Filmetrics® system, model number F10-RT-UV was used for the measurement of specular light transmission reflection and absorption. The light source is the combination of Halogen lamp and D2 lamp. Incident angle was 2 degrees, spectral reflectance R% and transmittance T% was measured by photo diode, for samples without scattering or haze.

The broadband light transmission and asymmetric light reflection characteristics of the anti-reflection structure of FIG. 1 is shown in FIG. 5, where the light transmittance and reflectance of an anti-reflection structure with molybdenum (Mo) as the light absorber layer. The light transmission in the visible range (400-750 nm) is fairly flat, showing the unique broadband light transmission property with an average T% of 31.8%. The asymmetric light reflectance (R%) showing the R% from the substrate side was 38.4%, and R% from the film side was 0.77%.

FIG. 6 shows the light transmittance and reflectance of the anti-reflection structures with tungsten (W) as the light absorber layer, demonstrating that changing the light absorber layer thickness (4 nm, 6 nm, 8 nm, and 10 nm), the light transmission may be tuned to meet the needs of various customers at various conditions.

FIG. 7 shows the light transmittance and reflectance of anti-reflection structures with tungsten (W) as the light absorber layer. The light transmittance throughout the visible range is very flat. The average T% is 30.5%. while it also shows the asymmetric light reflectance behavior, i.e., the R% from the substrate side is 38.4%, R% from film side is 0.91%.

FIG. 8 shows the light transmittance and reflectance of anti-reflection structures with tungsten (W) as the light absorber layer, with a low refractive index material LiF coated on the opposite side of the substrate. Average from wavelength 400-750 nm, T%=30.9%, the R% from the substrate side is 36.3%, R% from film side is 0.48%.

FIG. 9 shows the comparison of the light reflectance of FIG. 3 and FIG. 4 with and without low-n coating (LiF) on the other side of the substrate, respectively. The reflectance of incident light from the AR-structure coating side decrease from 0.91 % to 0.48%. The open circles is the element without LiF, and the filled circles are the element with LiF. The anti-reflection property doubled in the LiF configuration, and doubled the clarity of the view.

FIG. 10 shows the comparison of the light transmittance of FIG. 3 and FIG. 4 with and without low-n coating (LiF) on the other side of the substrate, respectively. In this example, the low-n coating did not show a significant effect on the light transmission (<0.5%). For the processes and/or methods disclosed, the functions performed in the processes and methods may be implemented in differing order, as may be indicated by context. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations.

It is to be understood that the embodiments disclosed herein do not thereby limit the scope of the disclosure; modifications and further applications of the disclosed principles as described herein are contemplated. The architectures, elements, structures, and/or devices described herein are non-limiting examples. Other architectures, elements, structures, and/or devices are also considered.

The terms used in this disclosure, and in the appended embodiments, are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including, but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes, but is not limited to,” etc.). In addition, if a specific number of elements is introduced, this may be interpreted to include at least the recited number, as may be indicated by context (e.g., the bare recitation of "two recitations," without other modifiers, includes at least two recitations, or two or more recitations). As used in this disclosure, any disjunctive word and/or phrase presenting two or more alternative terms should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

The terms and words used are not limited to the bibliographical meanings but are merely used to enable a clear and consistent understanding of the disclosure. It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

By the term "substantially" it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those skilled in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

Aspects of the present disclosure may be embodied in other forms without departing from its spirit or essential characteristics. The described aspects are to be considered in all respects illustrative and not restrictive. The embodied subject matter is indicated by the appended embodiments rather than by the foregoing description. All changes, which come within the meaning and range of equivalency of the embodiments, are to be embraced within their scope.