A convex high-reflection concave low-reflection color-blindness correction lens and a preparation method thereof

Abstract

The invention relates to a convex high-reflection concave low-reflection color blindness correction lens and a preparation method thereof. It solves the problems of limited design freedom, excessive number of film layers and stress in the prior art. It comprises a transparent lens substrate, a high-reflection film layer formed on the convex surface and a high-transmission film layer formed on the concave surface. The convex high-reflection film layer adopts a multilayer composite structure of silver and silicon dioxide, and through accurate control of the thickness of the silver layer and the matching of the dielectric layer, selective reflection and attenuation of specific color light are realized; the concave high-transmission film layer adopts a multilayer dielectric interference film system design of titanium dioxide and silicon dioxide, realizing accurate transmission and spectral shaping of each waveband. The advantages of the invention are: breaking through the design limitations of traditional single-sided coating, adopting a double-sided asymmetric film system synergistic control strategy, realizing higher spectral selectivity, lower stray light, more natural lens appearance and standardized production of eight types of clinical prescriptions.

Description

Technical Field

[0001] This invention relates to the field of lens technology, specifically to a stained and hardened color blindness correction lens based on micro-nano structures and its preparation method. Background Technology

[0002] Color blindness is a common visual impairment, primarily characterized by a reduced or lost ability to distinguish certain colors. Statistics show that approximately 200 million people worldwide suffer from varying degrees of color blindness, with red-green color blindness and red-green color blindness being the most common. Color-blind individuals face numerous inconveniences in their daily lives, including learning, work, and safe travel. Therefore, developing effective color blindness correction methods has significant social and clinical value.

[0003] Currently, eyeglass lenses used for color blindness correction are mainly divided into two categories:

[0004] The first type is tinted lenses, which attenuate specific colors of light by doping the lens material with organic dyes or metal complexes, utilizing the selective absorption properties of the dye molecules. For example, adding dye molecules that absorb green light to the lens material can enhance the ability of red-green colorblind patients to distinguish between red and green. However, tinted lenses have the following technical drawbacks:

[0005] (1) Dye molecules have a wide absorption spectrum and poor spectral selectivity, making it difficult to achieve a steep cutoff edge;

[0006] (2) Dye absorption will lead to a significant reduction in total visible light transmittance, resulting in a darker field of view and a poor visual experience for the wearer;

[0007] (3) Organic dyes are prone to photobleaching under long-term light exposure, which leads to a decrease in the corrective effect and a limited service life.

[0008] The second type is coated lenses. Chinese patent CN2149637Y discloses a "color vision correction spectacle lens," the technical solution of which involves coating the concave surface of a glass lens with a multilayer dielectric interference film stack. The film stack materials are titanium dioxide (TiO2) and silicon dioxide (SiO2), and the film is deposited onto the concave surface of the lens by vacuum evaporation. This technology utilizes the interference effect of light to change the spectral transmittance of the lens, and compared with tinted lenses, it has better spectral selectivity and higher visible light transmittance. However, this technology still has the following shortcomings:

[0009] (1) Coating only on the concave side of the lens limits the design freedom and makes it difficult to achieve deep bandgap suppression while maintaining high passband transmittance.

[0010] (2) Pure dielectric film systems have limited ability to suppress the stopband band. Usually, it is necessary to increase the number of film layers (>40 layers) to enhance the suppression effect. However, increasing the number of film layers will lead to increased film stress and increased risk of cracking.

[0011] (3) Single-sided coated lenses often have obvious interference colors (such as purplish-red or cyan-green), which are not aesthetically pleasing. Some patients refuse to wear them because of their appearance.

[0012] (4) The spectral curves were not designed in a refined manner for different types and degrees of color blindness, making it impossible to achieve standardized production of "prescription glasses according to the shape".

[0013] In recent years, double-sided coating technology has matured in high-end optical filters, laser protective glasses, and astronomical observation filters. By depositing different functional films on the front and back surfaces of optical components, more complex spectral modulation effects can be achieved. However, existing double-sided coating technologies struggle to apply the synergistic design of double-sided asymmetric film systems to the field of color blindness correction and precisely correspond to the eight clinical prescriptions for different types of color blindness. Summary of the Invention

[0014] The purpose of this invention is to address the aforementioned technical problems by providing a convex high-reflectivity, concave low-reflectivity colorblindness correcting lens and its manufacturing method. Through the synergistic design of a convex metal-dielectric composite reflective film and a concave all-dielectric antireflective film, the limitations of existing single-sided coating technology are overcome, achieving higher spectral selectivity, lower stray light, a more natural lens appearance, and standardization for eight types of clinical prescriptions.

[0015] To achieve the above objectives, the present invention adopts the following technical solution: a convex high-reflectivity and concave low-reflectivity color blindness correction lens, comprising a transparent lens substrate, the transparent lens substrate having a convex surface and a concave surface respectively, the convex surface having a convex high-reflectivity film layer formed by alternating stacking of a metallic silver layer and a silicon dioxide dielectric layer, and the concave surface having a concave high-reflectivity film layer, the convex high-reflectivity film layer and the concave high-reflectivity film layer forming at least one stop band and at least one pass band in the visible light band, the average transmittance in the stop band being ≤10%, and the average transmittance in the pass band being ≥90%.

[0016] In the aforementioned convex high-reflection and concave low-reflection color blindness correction lens, the concave high-reflection coating is a multilayer dielectric interference film system composed of alternating stacked titanium dioxide high-refractive-index layers and silicon dioxide low-refractive-index layers, with a total number of layers ranging from 5 to 50 and a total thickness ranging from 50 nm to 1000 nm.

[0017] In the aforementioned convex high-reflectivity and concave low-reflectivity color blindness correction lens, the number of metallic silver layers is 2 to 10, and the thickness of a single metallic silver layer is 3 nm to 30 nm; the outermost layer of the convex high-reflectivity film layer 2 is a hydrophobic layer of polyfluoride compound with a thickness ranging from 5 nm to 20 nm, and the protective layer is magnesium fluoride.

[0018] In the aforementioned convex high-reflection and concave low-reflection color blindness correction lens, the transparent lens substrate is selected from CR-39, polycarbonate, polyurethane, or optical glass, with a refractive index of 1.20~1.90.

[0019] A method for preparing the above-mentioned lens is provided, comprising the following steps:

[0020] Step 1: Select the target curve based on the target color blindness type;

[0021] Step 2: Optimize the film structure parameters of the convex high-reflection film and the concave high-reflection film using optical thin film design software;

[0022] Step 3: A silver layer and a silicon dioxide dielectric layer are sequentially deposited on the convex surface of the transparent lens substrate using a magnetron sputtering process to form a convex high-reflectivity film layer.

[0023] Step 4: On the concave surface of the transparent lens substrate, a high-refractive-index titanium dioxide layer and a low-refractive-index silicon dioxide layer are deposited sequentially using an electron beam evaporation combined with ion-assisted deposition process to form a concave high-reflection coating layer.

[0024] Step 5: Perform low-temperature annealing on the coated lens in a vacuum or protective atmosphere. The annealing temperature is 120°C to 180°C, and the holding time is 1 to 2 hours.

[0025] In step three, the magnetron sputtering process parameters are: background vacuum ≤ 5 × 10⁻ 4 Pa, working gas is argon, pressure 0.3~0.8 Pa, silver target sputtering power 1~3 W / cm², silicon dioxide target sputtering power 3~6 W / cm² (RF sputtering), substrate temperature ≤80℃.

[0026] In the electron beam evaporation process in step four, ion source-assisted deposition is used. The working gas of the ion source is a mixture of oxygen and argon. The ion beam energy is 100~300 eV, the ion beam current density is 50~150 µA / cm², and the substrate temperature is 80~120℃. The distance between the substrate and the evaporation source is 400~600 mm. The evaporation rate is 0.2~0.5 nm / s for titanium dioxide and 0.5~1.0 nm / s for silicon dioxide.

[0027] The low-temperature annealing process in step five is carried out in a vacuum of ≤1×10⁻²Pa or a high-purity nitrogen protective atmosphere, with a heating rate of 1~3℃ / min. After annealing, the furnace is cooled to below 60℃ and then removed.

[0028] The coating sequence for steps three and four is to first coat a convex high-reflection coating, then coat a concave high-reflection coating, and perform edge protection treatment on the lens between the two coatings.

[0029] The synergistic effect of a convex high-reflectivity coating and a concave high-anti-reflection coating can be expressed by the following mathematical formula:

[0030] Let the incident light intensity be I0(λ).

[0031] The reflectance of the convex high-reflectivity film layer 2 to wavelength λ is R_convex(λ).

[0032] The transmittance is T_convex(λ).

[0033] Let the transmittance of the concave high-reflection coating layer for wavelength be T_concave(λ), then the total transmittance of the lens is:

[0034] T_total(λ) = T_convex(λ) × T_concave(λ),

[0035] Since T_convex(λ) = 1 - R_convex(λ), substituting, we get:

[0036] T_total(λ) = [1 - R_convex(λ)] × T_concave(λ).

[0037] Compared with the prior art, the advantages of the present invention are as follows:

[0038] Significantly enhanced spectral selectivity: The synergistic effect of convex surface reflection and concave surface antireflection improves the band-stop suppression capability by 30%~50% compared to single-sided coating (such as CN2149637Y), while maintaining the passband transmittance above 90%. Through the multiplicative superposition effect, under the same total transmittance target, the number of single-sided film layers required for double-sided design is reduced by 30%~40% compared to single-sided design.

[0039] Stray light is significantly reduced: The convex high-reflectivity coating reflects light of the target wavelength back to the outside, instead of absorbing or scattering it inside the lens as in traditional single-sided coatings. This reduces stray light inside the lens, improves image contrast, and provides a clearer visual experience for the wearer.

[0040] Brighter field of vision: The passband transmittance of ≥90% ensures ample visual brightness. Compared with traditional metal-coated lenses (transmittance of 40%~60%), the wearer's visual brightness is increased by 40%~60%.

[0041] More natural appearance: Traditional single-sided dielectric interference film lenses often exhibit noticeable purplish-red or bluish-green reflections due to interference effects, making them highly recognizable and causing some patients to refuse to wear them due to their appearance. This invention controls the lens's appearance color through a high-reflectivity film layer (the silver layer reflects a neutral silver-gray), and further optimizes the outermost layer of the concave high-reflection coating layer with low refractive index (average reflectivity ≤1.5%), resulting in a very light neutral gray lens that closely resembles ordinary eyeglass lenses, significantly improving aesthetics.

[0042] Improved durability: The silver layer is encased in multiple layers of silica dielectric, with the outermost layer being a dense silica protective layer (80-150nm thick), providing excellent scratch resistance and oxidation resistance. Both titanium dioxide and silica are inorganic oxides, chemically extremely stable, and do not exhibit the photobleaching issues associated with organic dyes, allowing the lenses to last for decades.

[0043] Eight types of standardized prescriptions: This invention pre-sets eight types of spectral curves, each with a clear range of transmittance parameters, which can directly correspond to the diagnostic results output by color blindness testing instruments (such as the FM-100 color vision test and the Ishihara color blindness test chart), realizing standardized production of "coating according to prescription" and facilitating clinical fitting and quality control.

[0044] The preparation method is reliable: the composite process of magnetron sputtering and ion-assisted evaporation takes into account both the high-quality deposition of the silver layer and the optical precision control of the dielectric film. The low-temperature annealing process effectively eliminates the film stress, ensuring the yield and consistency of mass production. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0046] Figure 2 This is a flowchart of the method of the present invention;

[0047] In the figure: transparent lens substrate 1, convex surface 11, concave surface 12, convex high reflective coating 2, concave high anti-reflection coating 3. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1-2 As shown, a convex high-reflectivity and concave low-reflectivity color blindness correction lens includes a transparent lens substrate 1. The transparent lens substrate 1 has a convex surface 11 and a concave surface 12. The surface of the convex surface 11 has a convex high-reflectivity film layer 2 formed by alternating stacks of a metallic silver layer and a silicon dioxide dielectric layer, with the general formula (Ag / SiO2). n Or SiO2 / (Ag / SiO2) nWhere n = 2~6. The concave surface 12 has a concave high-reflection coating layer 3, the outermost layer of which is a low-refractive-index silicon dioxide layer, the thickness of which is optimized to make the average reflectivity of the lens ≤1.0% in the 450nm~650nm wavelength band; the convex high-reflection coating layer 2 and the concave high-reflection coating layer 3 form at least one blocking band and at least one pass band in the visible light band, the center wavelength of the blocking band corresponds to the target color light band that color-blind patients cannot distinguish, the average transmittance in the blocking band is ≤10%, the center wavelength of the pass band corresponds to the non-target color light band that color-blind patients can distinguish normally, and the average transmittance in the pass band is ≥90%.

[0050] The core concept of this invention lies in the asymmetric collaborative design of the convex high-reflectivity film layer 2 and the concave high-reflectivity film layer 3.

[0051] Traditional single-sided coating methods concentrate all spectral modulation functions on one surface of the lens, resulting in limited design freedom, excessive number of coating layers, and prominent stress issues. This invention decomposes the spectral modulation function onto two surfaces of the lens:

[0052] Convex high-reflectivity film layer 2: It performs the function of "coarse filtering". Utilizing the high reflectivity of the metallic silver layer, it selectively reflects the target color light, reflecting a portion of the target wavelength light energy back to the outside, thereby reducing the amount of target wavelength light entering the lens.

[0053] Concave high-reflectivity membrane layer 3: It performs the "fine filtration" function, using a full-dielectric interference membrane system to further attenuate the remaining target wavelength light, while enhancing the transmittance of non-target wavelengths, ensuring that patients have a clear visual perception of non-target color light.

[0054] By employing this dual-sided synergistic strategy of "reflection first, antireflection later", a steeper spectral cutoff edge and higher passband transmittance can be achieved without increasing the number of single-sided film layers compared to single-sided coating.

[0055] Design and function of convex high-reflectivity film layer 2

[0056] The role of the silver layer: Silver possesses excellent optical properties in the visible light band. Silver's complex refractive index exhibits strong dispersion characteristics in the visible light range, and its reflectivity varies significantly with wavelength. Specifically, silver's reflectivity is approximately 92% near 450 nm, approximately 95% near 550 nm, and approximately 98% near 650 nm. Utilizing this property, by controlling the thickness of the silver layer (5~25 nm), a Fabry-Pérot resonant cavity structure can be formed, generating reflection peaks in specific wavelength bands. The thinner the silver layer, the wider the reflection peak and the lower the peak reflectivity; the thicker the silver layer, the narrower the reflection peak and the higher the peak reflectivity. Through the cascaded design of multiple silver layers, broadband high reflectivity in the target wavelength band can be achieved.

[0057] The role of the silicon dioxide dielectric layer: Silicon dioxide (SiO2), as a low refractive index dielectric layer (n≈1.46), acts as a spacer between the two silver metal layers, adjusting the optical coupling strength between the silver metal layers. Simultaneously, the SiO2 layer serves as a protective layer, isolating the silver metal layers from the external environment and preventing optical performance degradation caused by oxidation and sulfidation of the silver metal layers.

[0058] The principle of the film structure design: When incident light shines on a multilayer (Ag / SiO2) structure, interference occurs between the light reflected from each silver layer. By precisely designing the thickness of each silver layer and the thickness of the spacer layer, light in the target wavelength band can satisfy the constructive interference condition, forming a high reflection peak; while light in the non-target wavelength band satisfies the destructive interference condition, resulting in lower reflectivity. This design utilizes the dual advantages of the high reflectivity of the silver layers and the interference effect between the multilayer films.

[0059] Design and function of concave high anti-reflection film layer 3

[0060] A concave high-reflection coating 3 is formed on the concave surface 12 of the lens and is composed of alternating stacks of a high-refractive-index titanium dioxide layer (TiO2) and a low-refractive-index silicon dioxide layer (SiO2).

[0061] Material selection: Titanium dioxide (TiO2) has a refractive index of approximately 2.35–2.55 (depending on the deposition process and crystal phase), while silicon dioxide (SiO2) has a refractive index of approximately 1.46. The refractive index difference between the two is as high as 0.9–1.1, making it one of the material combinations with the largest refractive index difference in the visible light band. This large refractive index difference means that a smaller number of film layers can be used to achieve wide-band, high-precision spectral control, which is beneficial for reducing the total film thickness, reducing film stress, and improving film adhesion.

[0062] Film system design: Optical thin film design software (TFCalc, OptiLayer, etc.) is used to optimize the film system based on the target spectral transmittance curve. Commonly used film system structures include: bandpass filters (such as (HL)^mH (LH)^m), notch filters, long-pass / short-pass edge filters, etc. By adjusting the thickness of each layer, stopbands (low transmittance) and passbands (high transmittance) can be formed in specific wavelength bands.

[0063] Synergy with the convex 11 film: The design of the concave 12 film needs to take into account the fact that the convex 11 film has already pre-reflected a portion of the target wavelength light. Therefore, the target value of the stopband transmittance of the concave 12 film can be set higher than that of the single-sided design (for example, a single-sided design may require a stopband transmittance of ≤5%, while a double-sided synergistic design only needs ≤10% to achieve the same final transmittance). This reduces the design difficulty of the concave 12 film and reduces the number of film layers required.

[0064] The concave high-reflection coating layer 3 is configured to form an anti-reflection effect in at least one of the following wavelength bands:

[0065] ① In the 440nm±15nm wavelength band, the transmittance is ≥85%;

[0066] ② In the 540nm±15nm wavelength band, the transmittance can be configured from 5% to 40% depending on the type of color blindness;

[0067] ③ In the 630nm±15nm band, the transmittance can be configured to 75%~95% depending on the type of color blindness.

[0068] When the convex high-reflectivity film 2 and the concave high-reflection film 3 are combined, eight preset spectral transmittance curves are formed, corresponding to:

[0069] Mild red-green color blindness, moderate red-green color blindness, severe red-green color blindness;

[0070] Mild green blindness, moderate green blindness, severe green blindness;

[0071] Blue-yellow color blindness;

[0072] Full color weak.

[0073] The transmittance of the eight preset spectral transmittance curves at 440nm, 540nm, and 630nm is configured according to the following ranges:

[0074] 1 Mild red-blindness ≥80% 15~30% 85~95% 2 Moderate red-blindness ≥80% 8~20% 80~90% 3 Severe red-blindness ≥80% 3~12% 75~85% 4 Mild green blindness ≥80% 25~40% ≥80% 5 Moderate green blindness ≥80% 15~30% ≥80% 6 Severe green blindness ≥80% 5~18% ≥80% 7 Blue-yellow blindness 15~35% ≥75% ≥80%

[0075] Matching eight types of spectral curves with color blindness types

[0076] The mechanism of color blindness is related to the functional abnormalities of three types of cone cells in the retina (L-red, M-green, and S-blue). Protanopia (red-red blindness) is characterized by the absence or abnormality of L-cone cells, resulting in decreased sensitivity to long-wavelength light (red). The main problem is confusion between red and green, with green (around 540nm) appearing brighter than normal. Deuteranopia (green-green blindness) is characterized by the absence or abnormality of M-cone cells, resulting in decreased sensitivity to medium-wavelength light (green). Tritanopia (blue-yellow blindness) is characterized by abnormal S-cone cells, resulting in decreased sensitivity to short-wavelength light (blue). Achromatomaly (total color weakness) is characterized by weak function of all cone cells.

[0077] Based on the mechanism of color blindness, the correction principle of this invention is as follows: For patients with red-green color blindness, by setting a blocking band around 540nm (green light), the transmittance of green light is reduced, rebalancing the input signal intensity of L-cone and M-cone cells, enabling patients to distinguish red and green more clearly. For patients with blue-yellow color blindness, by setting a blocking band around 440nm (blue light), the blue-yellow contrast is adjusted. For patients with total color weakness, it is necessary to appropriately reduce the transmittance of all wavelengths while maintaining a relative balance of transmittance across the three wavelengths.

[0078] Based on the above principles and combined with clinical practice's classification of color blindness severity (mild, moderate, severe), this invention pre-defines eight types of spectral transmittance curves, corresponding to mild red-blindness, moderate red-blindness, severe red-blindness, mild green-blindness, moderate green-blindness, severe green-blindness, blue-yellow-blindness, and total color weakness, respectively. Specific transmittance parameters for each type of curve are shown in the table above.

[0079] Among them, the convex high reflectivity film layer 2 is a multilayer composite film structure formed by alternating stacking of metallic silver layer and silicon dioxide dielectric layer, and the total number of layers of the convex high reflectivity film layer 2 is 8 to 30 layers, and the thickness of a single silicon dioxide dielectric layer is 5nm to 50nm; the concave high antireflection film layer 3 is a multilayer dielectric interference film system formed by alternating stacking of titanium dioxide high refractive index layer and silicon dioxide low refractive index layer, with a total number of layers of 5 to 50 layers and a total thickness of 50nm to 1000nm.

[0080] By adjusting the matching relationship between the silver layer thickness and the dielectric layer thickness, at least one of the following effects can be achieved:

[0081] ① A reflection peak is formed in the 540nm±20nm wavelength band, with a reflectivity ≥60%;

[0082] ② A reflection peak is formed in the 630nm±20nm wavelength band, with a reflectivity ≥50%;

[0083] ③ A reflection peak is formed in the 440nm±20nm band, with a reflectivity ≥40%.

[0084] As can be seen, the number of metallic silver layers is 2 to 10, and the thickness of a single metallic silver layer is 3 nm to 30 nm; the outermost layer of the convex high-reflectivity film layer 2 is a hydrophobic layer of polyfluoride compound with a thickness ranging from 5 nm to 20 nm, and the protective layer is magnesium fluoride with a thickness ranging from 10 nm to 50 nm, which is used to protect the silver layer from oxidation and mechanical damage, while reducing the reflective glare of the convex surface 11.

[0085] Furthermore, the transparent lens substrate 1 is selected from CR-39, polycarbonate (PC), polyurethane (PU) or optical glass, and has a refractive index of 1.20~1.90.

[0086] like Figure 2The following is a method for preparing a convex high-reflectivity, concave low-reflectivity colorblindness corrective lens, comprising the following steps:

[0087] Step 1: Select the target curve from the eight types of spectral transmittance curves based on the target color blindness type;

[0088] Step 2: Optimize the film structure parameters of the convex high-reflection film 2 and the concave high-reflection film 3 respectively using optical thin film design software (TFCalc or OptiLayer);

[0089] Using TFCalc or OptiLayer software, with the target spectral transmittance curve as the objective function and film thickness as the variable, an optimization algorithm combining the needle method and gradient method was employed for film system optimization. The optimization process must consider the refractive index dispersion of the lens substrate, the refractive index dispersion of the film material, and the absorption coefficient.

[0090] Step 3: On the convex surface 11 of the transparent lens substrate 1, a metallic silver layer and a silicon dioxide dielectric layer are sequentially deposited using a magnetron sputtering process to form a convex high-reflectivity film layer 2.

[0091] The reasons for choosing magnetron sputtering over evaporation are as follows:

[0092] (1) Magnetron sputtering deposited silver layers have high density, fine grains, and smooth surfaces, which is beneficial for obtaining higher reflectivity and lower scattering loss;

[0093] (2) The adhesion of the film layer produced by magnetron sputtering is better than that of the evaporated film, and the silver layer is not easy to fall off;

[0094] (3) Magnetron sputtering can be performed at a lower substrate temperature (≤80℃) and is suitable for heat-sensitive organic lens materials (such as CR-39, PC).

[0095] Reasons for selecting process parameters: Argon pressure of 0.3~0.8Pa can ensure that sputtered particles have enough energy to reach the substrate while avoiding excessive collision scattering; silver target power of 1~3W / cm² can ensure a stable sputtering rate while avoiding overheating of the silver target; substrate rotation of 5~15rpm can ensure that the film thickness uniformity reaches within ±2%.

[0096] Step 4: On the concave surface 12 of the transparent lens substrate 1, a high refractive index layer of titanium dioxide and a low refractive index layer of silicon dioxide are deposited sequentially using an electron beam evaporation combined with ion-assisted deposition process to form a concave high anti-reflection film layer 3.

[0097] The reasons for choosing electron beam evaporation combined with ion-assisted deposition are as follows:

[0098] (1) Ion beam bombardment can improve the density of the film and make the refractive index of the film close to the value of the bulk material, which is beneficial to the precise control of the spectral curve; (2) Ion assistance can significantly improve the adhesion of film layers, especially the adhesion of TiO2 layers on organic substrates;

[0099] (3) Ion assistance can reduce film absorption and increase passband permeability. The reason for choosing O2:Ar mixture as the ion source gas is that O2 is used to compensate for the oxygen lost by TiO2 during deposition, avoiding the formation of oxygen-deficient TiOx (increased absorption); Ar is used to improve bombardment efficiency. The reason for choosing a substrate temperature of 80~120℃ is that if the temperature is too low, the film layer will be loose, and if the temperature is too high, the organic substrate will be easily deformed.

[0100] Step 5: Perform low-temperature annealing on the coated lens in a vacuum or protective atmosphere. The annealing temperature is 120°C to 180°C, and the holding time is 1 to 2 hours.

[0101] The functions of annealing include:

[0102] (1) Eliminate internal stress in the membrane layer and reduce the risk of membrane cracking;

[0103] (2) Promotes the crystallization and oxidation of TiO2 film, further increasing the refractive index and reducing absorption;

[0104] (3) To stabilize the growth of silver grains and improve the long-term stability of the silver layer. Reason for choosing a protective atmosphere: The silver layer is easily oxidized at high temperatures, and a protective atmosphere can prevent the silver layer from oxidizing and discoloring.

[0105] In step three, the magnetron sputtering process parameters are: background vacuum ≤ 5 × 10⁻ 4 The working gas is argon (purity ≥99.999%), pressure 0.3~0.8Pa, silver target sputtering power 1~3W / cm², silicon dioxide target sputtering power 3~6W / cm² (RF sputtering), substrate temperature ≤80℃. The substrate rotation speed during sputtering is 5~15rpm to ensure film thickness uniformity.

[0106] In the electron beam evaporation process of step four, ion source-assisted deposition is used. The working gas of the ion source is a mixture of oxygen and argon (volume ratio 1:1~3:1), the ion beam energy is 100~300eV, the ion beam current density is 50~150µA / cm², and the substrate temperature is 80~120℃. During the deposition process, an optical film thickness monitor is used to control the thickness of each layer in real time, with a thickness control accuracy better than ±0.5nm. The distance between the substrate and the evaporation source is 400~600mm, and the evaporation rate is 0.2~0.5nm / s for titanium dioxide and 0.5~1.0nm / s for silicon dioxide.

[0107] The low-temperature annealing in step five is carried out in a protective atmosphere of vacuum degree ≤1×10⁻²Pa or high-purity nitrogen (purity ≥99.999%) to prevent silver layer oxidation. The heating rate is 1~3℃ / min. After annealing, the silver layer is cooled to below 60℃ in the furnace and then removed.

[0108] After annealing, the average transmittance of the lens in the visible light band increases by 3%~8%, the internal stress of the film layer decreases by 30%~50%, and the adhesion of the film layer passes the 3M tape peel test (100 / 100 no peeling).

[0109] The coating sequence for steps three and four is as follows: first, deposit the convex high-reflectivity coating layer 2, then deposit the concave high-reflectivity coating layer 3, and perform edge protection treatment on the lens between the two coating processes to prevent cross-contamination during double-sided coating.

[0110] The synergistic effect of the convex high-reflection coating layer 2 and the concave high-reflection coating layer 3 is expressed by the following mathematical formula:

[0111] Let the incident light intensity be I0(λ).

[0112] The reflectance of the convex high-reflectivity film layer 2 to wavelength λ is R_convex(λ).

[0113] The transmittance is T_convex(λ), (satisfying R_convex+T_convex=1, ignoring absorption). Light passing through the convex high-reflectivity film 2 enters the transparent lens substrate 1, propagates inside the transparent lens substrate 1, and reaches the concave high-reflectivity film 3.

[0114] Let the transmittance of the concave high-reflection coating layer 3 for wavelength pair be T_concave(λ) (reflection loss at the interface between the concave 12 film and air has been considered). Then the total transmittance of the lens is:

[0115] T_total(λ)=T_convex(λ)×T_concave(λ),

[0116] Since T_convex(λ) = 1 - R_convex(λ), substituting this gives:

[0117] T_total(λ)=[1-R_convex(λ)]×T_concave(λ).

[0118] As can be seen from the formula, for the target wavelength band (requiring low transmittance), this can be achieved in two ways: first, by increasing the reflectivity R_convex(λ) of the convex 11 film (reflecting light back to the outside), and second, by decreasing the transmittance T_concave(λ) of the concave 12 film. These two methods have a multiplicative effect. For example, if R_convex = 0.5 (50% reflection) and T_concave = 0.2 (20% transmittance), then T_total = 0.1 (10% transmittance). If only the concave 12 film is used without the convex 11 film (R_convex = 0), to achieve T_total = 0.1, T_concave = 0.1 is required, meaning the concave 12 film needs to achieve 90% attenuation, which typically requires more film layers.

[0119] For non-target bands (where high transmittance is required), it is necessary to simultaneously satisfy R_convex(λ) as small as possible and T_concave(λ) as close to 1 as possible.

[0120] Therefore, the core advantage of the dual-surface collaborative design is that it decomposes the spectral modulation task into two surfaces, with each surface undertaking a moderate modulation task, thereby reducing the design difficulty of a single surface and the number of film layers required.

[0121] Example 1: Dual-film synergistic lenses for moderate red-light blindness

[0122] 1. Target spectral curve

[0123] The parameter range for Type 2 (moderate red-blindness) is determined as follows:

[0124] 440nm±15nm band: Average transmittance ≥85%;

[0125] 540nm±15nm band: average transmittance 8~20% (target value 12%);

[0126] 630nm±15nm band: average transmittance 80~90% (target value 88%);

[0127] Average reflectivity in the 450~650nm band: ≤1.5%.

[0128] 2. Design of convex high-reflectivity film layer

[0129] Substrate: CR-39 (refractive index 1.498, Abbe number 58);

[0130] Membrane structure: CR-39 / (Ag / SiO2)3 / SiO2;

[0131] Thickness of each layer (nm):

[0132] Layer 1 (Ag): 8.2;

[0133] Second layer (SiO2): 64.5;

[0134] Layer 3 (Ag): 10.1;

[0135] 4th layer (SiO2): 69.3;

[0136] Layer 5 (Ag): 7.8;

[0137] 6th layer (SiO2): 58.6;

[0138] 7th layer (SiO2 protective layer): 92.0.

[0139] Design principle: A three-layer silver structure is used. By adjusting the thickness of the middle silver layer (10.1nm) to be greater than that of the two side silver layers (8.2nm and 7.8nm), the center of the reflection peak is located near 540nm, and the peak reflectivity is about 58%. The cascade effect of the three silver layers makes the reflection bandwidth cover 520~560nm.

[0140] 3. Concave high-reflection coating layer design

[0141] Membrane structure: CR-39 / (TiO2 / SiO2) 12 ;

[0142] Total number of floors: 24;

[0143] Total thickness: 1670nm;

[0144] Thickness of each layer (nm):

[0145] (TiO2 / SiO2 alternation, thickness optimized from the center to both sides, specific values ​​omitted)

[0146] Design principle: A multi-cavity bandpass filter structure is adopted to form a notch stop band near 540nm, while anti-reflection regions are formed near 440nm and 630nm.

[0147] 4. Preparation process

[0148] Convex 11 coating: Magnetron sputtering equipment (NAURA), base vacuum 4×10⁻ 4 Pa, Ar gas pressure 0.55 Pa, Ag target power 2.2 W / cm² (DC), SiO2 target power 4.5 W / cm² (RF 13.56 MHz), substrate temperature 65℃, substrate rotation 10 rpm. Coating time: Ag layer approximately 45 seconds / layer, SiO2 layer approximately 120 seconds / layer.

[0149] Concave 12 coating: Electron beam evaporation equipment (Optorun) equipped with an APS ion source. Base vacuum 1.0 × 10⁻ 4Pa, ion source O2:Ar=2:1, ion beam energy 200eV, beam current density 100µA / cm², substrate temperature 95℃. TiO2 evaporation rate 0.3nm / s, SiO2 evaporation rate 0.7nm / s. Optical film thickness monitoring (wavelength 550nm), accuracy ±0.3nm.

[0150] Annealing: Under a high-purity N2 protective atmosphere (purity 99.999%, flow rate 5L / min), heat to 150℃ at a heating rate of 2℃ / min, hold for 1.5 hours, and then remove from the furnace at 55℃.

[0151] 5. Test Results

[0152] Spectral transmittance (PerkinElmer Lambda 950 spectrophotometer):

[0153] Average transmittance in the 520-560nm range: 10.2%;

[0154] Average transmittance in the 610-700nm range: 92.8%;

[0155] Average transmittance in the 440-480nm range: 88.1%;

[0156] Average reflectivity (450-650nm): 1.15%;

[0157] Film adhesion: 3M tape peel test 100 / 100, no peeling;

[0158] Abrasion resistance of the membrane layer: No scratches after 100 cycles of 0000# steel wool;

[0159] High temperature and high humidity test (60℃ / 90%RH / 240 hours): transmittance change ≤1.5%.

[0160] 6. Clinical trial fitting

[0161] Subjects: 10 patients with moderate red-blindness (diagnosed by Ishihara color blindness test chart and FM-100 color vision test), aged 18-45 years.

[0162] Wearing time: ≥4 hours per day for 4 weeks.

[0163] Test results:

[0164] Ishihara color blindness test chart correct recognition rate: average 42% before wearing, average 94% after 4 weeks of wearing.

[0165] FM-100 color vision test total error score: average 185 before wearing, average 32 after 4 weeks of wearing.

[0166] Subjective ratings (1-10 points): Visual clarity average 8.7 points, comfort average 9.1 points, and appearance acceptability average 9.3 points.

[0167] No adverse events reported

[0168] Example 2: Dual-film synergistic lenses for severe green blindness

[0169] 1. Target spectral curve

[0170] The parameter range for Type 6 (severe green-green color blindness):

[0171] 440nm±15nm: ≥85%;

[0172] 540nm±15nm: 5~18% (target value 6%);

[0173] 630nm±15nm: ≥80% (target value 85%).

[0174] 2. Design of convex high-reflectivity film layer

[0175] Membrane structure: CR-39 / (Ag / SiO2)4 / SiO2;

[0176] Silver layer thickness (nm): 6.5 / 8.2 / 6.8 / 8.5;

[0177] SiO2 spacer layer thickness (nm): 55.2 / 60.1 / 56.3 / 62.5;

[0178] Protective layer SiO2: 105.0 nm;

[0179] Designed reflection peak: center wavelength 545nm, peak reflectivity 67%.

[0180] 3. Concave high-reflection coating layer design

[0181] Membrane structure: CR-39 / (TiO2 / SiO2) 15 ;

[0182] Total number of floors: 30;

[0183] A dual notch design is adopted to form a deep stopband in the 530~560nm range (transmittance target ≤5%).

[0184] 4. Preparation process

[0185] Similar to Example 1, the number of film layers on the concave surface 12 is increased to 30 layers, and the coating time is extended by about 25%.

[0186] 5. Test Results

[0187] Average transmittance in the 520-560nm range: 4.8%;

[0188] Average transmittance in the 610-700nm range: 86.5%;

[0189] Average transmittance in the 440-480nm range: 89.2%;

[0190] Average reflectance: 1.3%.

[0191] 6. Clinical trial fitting

[0192] Subjects: 8 patients with severe green-blindness.

[0193] Test results: The correct recognition rate of the Ishihara color blindness test chart increased from 35% to 91%, and the total error score of FM-100 decreased from 210 to 28.

[0194] Example 3: Dual-film synergistic lenses for blue-yellow color blindness

[0195] 1. Target spectral curve

[0196] The parameter range for Type 7 (blue-yellow blindness):

[0197] 440nm±15nm: 15~35% (target value 25%);

[0198] 540nm±15nm: ≥75% (target value 80%)

[0199] 630nm±15nm: ≥80% (target value 85%)

[0200] 2. Design of convex high-reflectivity film layer

[0201] Membrane structure: CR-39 / (Ag / SiO2)3 / SiO2;

[0202] Silver layer thickness (nm): 7.5 / 9.0 / 7.0;

[0203] SiO2 spacer layer thickness (nm): 50.0 / 52.0 / 48.0;

[0204] Protective layer SiO2: 95.0 nm;

[0205] Designed reflection peak: center wavelength 440nm, peak reflectance 45%;

[0206] 3. Concave high-reflection coating layer design

[0207] Membrane structure: CR-39 / (TiO2 / SiO2) 10 ;

[0208] Total number of floors: 20;

[0209] A notch band is formed at 430-450nm, while maintaining high transmittance at 540nm and 630nm.

[0210] 4. Test Results

[0211] Average transmittance in the 430-450nm range: 24.5%;

[0212] Average transmittance at 530-550nm: 82.3%;

[0213] Average transmittance in the 610-700nm range: 86.7%.

[0214] In summary, the principle of this embodiment is as follows: by precisely controlling the thickness of the metallic silver layer and matching it with the dielectric layer, selective reflection and attenuation of specific colors of light are achieved; the concave high-reflection coating layer 3 adopts a multilayer dielectric interference film system design of titanium dioxide and silicon dioxide to achieve precise anti-reflection and spectral shaping for each wavelength band. Through the synergistic effect of the reflection of the convex surface 11 and the anti-reflection of the concave surface 12, the transmittance and reflectance of different light bands are precisely controlled, forming eight standardized spectral transmittance curves corresponding to the eight types of color blindness. This invention breaks through the design limitations of traditional single-sided coatings, adopts a double-sided asymmetric film system synergistic control strategy, and achieves higher spectral selectivity, lower stray light, a more natural lens appearance, and eight types of clinical prescriptions that can be standardized for production.

[0215] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0216] Although this document frequently uses terms such as transparent lens substrate 1, convex surface 11, concave surface 12, convex high-reflection film layer 2, and concave high-reflection film layer 3, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A convex high-reflectance, concave low-reflectance colorblindness corrective lens, comprising a transparent lens substrate (1), wherein the transparent lens substrate (1) has a convex surface (11) and a concave surface (12), characterized in that, The convex surface (11) has a convex high-reflectivity film layer (2) formed by alternating stacks of metallic silver layers and silicon dioxide dielectric layers, and the concave surface (12) has a concave high-reflectivity film layer (3). The convex high-reflectivity film layer (2) and the concave high-reflectivity film layer (3) form at least one stopband and at least one passband in the visible light band. The average transmittance in the stopband is ≤10%, and the average transmittance in the passband is ≥90%. The concave high-reflectivity film layer (3) is a multilayer dielectric interference film system formed by alternating stacks of titanium dioxide high-refractive-index layers and silicon dioxide low-refractive-index layers. The total number of layers is 5 to 50, and the total thickness is 50 nm to 1000 nm. The number of metallic silver layers is 2 to 10. The thickness of a single layer of metallic silver is 3nm to 30nm; the outermost layer of the convex high reflectivity film (2) is a hydrophobic layer of polyfluoride compound with a thickness range of 5nm-20nm, and the protective layer is magnesium fluoride; the convex high reflectivity film (2) performs the function of "coarse filtration", using the high reflectivity of the metallic silver layer to selectively reflect the target color light, reflecting a portion of the target wavelength light energy back to the outside, thereby reducing the target wavelength light flux entering the lens; the concave high anti-reflection film (3) performs the function of "fine filtration", using the all-dielectric interference film system to further attenuate the remaining target wavelength light, while enhancing the non-target wavelength light, ensuring that the patient obtains clear visual perception of non-target color light.

2. The colorblindness correcting lens with a convex high-reflectivity surface and a concave low-reflectivity surface according to claim 1, characterized in that, The transparent lens substrate (1) is selected from CR-39, polycarbonate, polyurethane or optical glass, and has a refractive index of 1.20~1.

90.

3. A method for preparing the lens according to any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Select the target curve based on the target color blindness type; Step 2: Optimize the film structure parameters of the convex high-reflection film (2) and the concave high-reflection film (3) respectively using optical thin film design software; Step 3: On the convex surface (11) of the transparent lens substrate (1), a metallic silver layer and a silicon dioxide dielectric layer are deposited sequentially by magnetron sputtering to form a convex high-reflectivity film layer (2). Step 4: On the concave surface (12) of the transparent lens substrate (1), a high refractive index layer of titanium dioxide and a low refractive index layer of silicon dioxide are deposited sequentially using an electron beam evaporation combined with ion-assisted deposition process to form a concave high anti-reflection film layer (3). Step 5: Perform low-temperature annealing on the coated lens in a vacuum or protective atmosphere. The annealing temperature is 120°C to 180°C, and the holding time is 1 to 2 hours.

4. The preparation method according to claim 3, characterized in that, In step three, the magnetron sputtering process parameters are: background vacuum ≤ 5 × 10⁻ 4 Pa, working gas is argon, pressure 0.3~0.8 Pa, silver target sputtering power 1~3 W / cm², silicon dioxide target sputtering power 3~6 W / cm² (RF sputtering), substrate temperature ≤80℃.

5. The preparation method according to claim 4, characterized in that, In the electron beam evaporation process in step four, ion source-assisted deposition is used. The working gas of the ion source is a mixture of oxygen and argon. The ion beam energy is 100~300 eV, the ion beam current density is 50~150 µA / cm², and the substrate temperature is 80~120℃. The distance between the substrate and the evaporation source is 400~600 mm. The evaporation rate is 0.2~0.5 nm / s for titanium dioxide and 0.5~1.0 nm / s for silicon dioxide.

6. The preparation method according to claim 5, characterized in that, The low-temperature annealing process in step five is carried out in a vacuum of ≤1×10⁻²Pa or a high-purity nitrogen protective atmosphere, with a heating rate of 1~3℃ / min. After annealing, the furnace is cooled to below 60℃ and then removed.

7. The preparation method according to claim 6, characterized in that, The coating sequence of steps three and four is as follows: first, a convex high-reflection coating layer (2) is coated, then a concave high-reflection coating layer (3) is coated, and edge protection treatment is performed on the lens between the two coatings.

8. The preparation method according to claim 7, characterized in that, The synergistic effect of the convex high-reflection film layer (2) and the concave high-reflection film layer (3) is expressed by the following mathematical formula: Let the incident light intensity be I0(λ). The reflectance of the convex high-reflectance film layer (2) to wavelength λ is R_convex(λ). The transmittance is T_convex(λ). Let the transmittance of the concave high-reflection coating layer (3) for wavelength be T_concave(λ), then the total transmittance of the lens is: T_total(λ) = T_convex(λ) × T_concave(λ), Since T_convex(λ) = 1 - R_convex(λ), substituting, we get: T_total(λ) = [1 - R_convex(λ)] × T_concave(λ).

Images