Cosmetic contact lens with automatic orientation function and preparation method thereof

Abstract

The invention discloses a cosmetic contact lens with an automatic orientation function and a preparation method thereof, and relates to the technical field of contact lens manufacturing, the cosmetic contact lens comprises a lens body, a vertical thinning area is arranged in the 3-9 o'clock direction of the lens body, the width of the vertical thinning area accounts for 1 / 3 of the circumferential direction, the vertical thinning area covers the position from the center to 6.5 mm in the radial direction, and the edge thickness of the vertical thinning area is 0.02-0.08 mm thinner than the center thickness; the upper edge of the lens body adopts a chamfer angle of 15-25 degrees, and the lower edge of the lens body is in a right-angle design to form a thickness difference; according to the invention, through the structural design of the vertical thinning area, the asymmetric edge and the micro groove, in combination with the shape memory hydrogel material and the biaxial numerical control cutting process, the precise orientation of the lens is realized by using the eyelid pressure and tear capillary effect, and meanwhile, the wearing comfort is improved through edge thinning and hydrophilic modification; and the production cost is reduced by 60% through an efficient forming process, and a high-precision, comfortable and economical solution is provided for a cosmetic contact lens orientation technology.

Description

Technical Field

[0001] The present invention relates to the technical field of contact lens manufacturing, and specifically to a colored contact lens with an automatic orientation function and a preparation method thereof. Background Art

[0002] In the application of colored contact lenses (colored contact lenses), the orientation stability of the lens is a key factor affecting the wearing effect. Traditional colored contact lenses usually lack an effective positioning structure, resulting in the rotation and offset of the lens pattern during wearing due to eye movement or eyelid movement, affecting the visual effect and aesthetics. In the prior art, the prism gravity method realizes positioning by increasing the thickness below the lens to form a gravity hanging effect, but this method will significantly increase the edge thickness of the lens (usually more than 0.2 mm), resulting in a strong foreign body sensation during wearing and poor long-term wearing comfort. Another commonly used laser marking positioning method can achieve a certain degree of orientation, but it relies on high-precision laser processing equipment, has strict requirements for the production process, high costs, and the marked area is easily affected by tear erosion, affecting the positioning reliability.

[0003] In addition, in the prior art, the lens material mostly uses ordinary hydrogel, with insufficient elastic modulus and recovery performance, unable to effectively respond to eyelid pressure to achieve dynamic positioning, and the edge structure design does not consider the hydrodynamic effect, and the uneven distribution of the tear film easily leads to lens sliding. To solve the above problems, there is an urgent need for a new type of colored contact lens and a preparation method thereof that take into account positioning accuracy, wearing comfort, and production feasibility.

[0004] In view of this, a colored contact lens with an automatic orientation function and a preparation method thereof are provided to overcome the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a colored contact lens with an automatic orientation function and a preparation method thereof to solve the problems raised in the above background art.

[0006] To solve the above technical problems, a colored contact lens with an automatic orientation function provided by the present invention includes a lens body:

[0007] A vertically thinned area is provided in the 3-9 o'clock direction of the lens body. The width of the vertically thinned area accounts for 1 / 3 of the circumferential direction, and radially covers from the center to 6.5 mm. Moreover, the edge thickness of the vertically thinned area is 0.02-0.08 mm thinner than the center thickness; the upper edge of the lens body is chamfered at 15-25°, and the lower edge maintains a right-angle design to form a thickness difference;

[0008] Micro-groove arrays are provided on the upper and lower edges of the lens body. The depth of the micro-grooves is 50-150 μm, the width is 100-300 μm, and they are evenly distributed in an array;

[0009] The lens body is made of a copolymer hydrogel of hydroxyethyl polymethacrylate and polyurethane acrylate, with an elastic modulus of 0.5 - 1.2 MPa and a recovery rate of ≥ 92%.

[0010] Furthermore, the central thickness of the vertical thinning area is 0.06 - 0.12 mm, the thickness of the edge thinning area is the central thickness - 0.08 mm, and the thickness gradient change rate is 0.004 mm / mm.

[0011] Furthermore, the width of the upper edge chamfer is 0.3 mm, the thickness of the upper edge is 0.13 mm, and the thickness of the lower edge is 0.15 mm, forming a thickness difference of 0.02 mm.

[0012] Furthermore, the micro - groove array is a strip - shaped groove, with a quantity of 50 and a spacing of 300 μm.

[0013] Furthermore, the surface of the lens body is treated by plasma to form a hydrophilic modification layer, with a contact angle ≤ 30°.

[0014] A preparation method of a colored contact lens with an automatic orientation function, characterized by including the following steps:

[0015] Biaxial numerical control cutting and forming: Fix the pre - polymerized hydrogel blank on a 5 - axis machine tool, perform gradient cutting on the radial 5.5 - 6.5 mm area in the 3 - 9 o'clock direction to form a vertical thinning area, with a thinning amount of 0.02 - 0.08 mm; at the same time, cut a 15 - 25° chamfer on the upper edge of the lens body, and keep the lower edge at a right angle to form an asymmetric edge structure;

[0016] Plasma surface treatment: Perform argon plasma treatment on the thinning area and the upper and lower edge groove areas, with a power of 50 - 100 W, a treatment time of 20 - 40 s, and a gas pressure of 80 - 120 Pa to form a hydrophilic modification layer with a contact angle ≤ 30°;

[0017] Thermo - forming and curing: Place the cut lens in a ceramic mold, and perform mold pressing at 120 - 140 °C and a pressure of 4 - 6 MPa for 3 - 7 minutes to shape the edge grooves and the asymmetric structure, with a material structure retention rate ≥ 98%;

[0018] Coloring and post - treatment: Immerse and stain with food - grade pigments in the coloring area at a temperature of 40 - 60 °C for 8 - 12 minutes, and then disinfect and package.

[0019] Furthermore, in the biaxial numerical control cutting and forming step, the diameter of the hydrogel blank is 13.0 - 14.5 mm, the thickness is 0.2 - 0.4 mm, the cutting accuracy is ± 0.001 mm, and the cutting speed is 8 - 12 mm / s.

[0020] Furthermore, in the plasma surface treatment step, the purity of argon gas is ≥99.99%, and the surface contact angle after treatment is reduced from 60° to 25-30°.

[0021] Furthermore, in the thermoforming and curing step, the cooling demoulding temperature is 20-30° C., and the edges are smoothed after demoulding, with a breakage rate of ≤1.5%.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Accurate dynamic positioning to solve the pattern rotation offset:

[0024] 1. Co-positioning of vertical thinning zone and asymmetric edge: set thickness gradient thinning zone (thinning amount 0.02-0.08mm) in the 3-9 o'clock direction of the lens, combine the thickness difference formed by the 15-25° chamfer of the upper edge and the right angle design of the lower edge, and use the 0.3N / mm applied by the upper eyelid to the thinning zone when blinking. 2 Pressure generates a directional deformation torque of 0.5° / time, prompting the thinned area of the lens to align in the vertical direction (12-6 o'clock). The directional capillary effect formed by the micro groove arrays on the upper and lower edges (depth 50-150μm, width 100-300μm) guides the tears to flow along the grooves at a speed of 0.1mm / s, achieving stable positioning of the lens along the vertical axis. After a simulated eye test, the rotation deviation angle was stabilized at 2.5° (≤3°) within 8 minutes, which improves the positioning accuracy by 83% compared with traditional lenses (deviation angle ≥15°), ensuring long-term and accurate alignment of the pattern, and solving the pattern offset problem caused by the lack of positioning structure in traditional lenses.

[0025] 2. Shape memory hydrogel material enhances positioning stability: Polyhydroxyethyl methacrylate and polyurethane acrylate copolymer hydrogel (elastic modulus 0.5-1.2MPa, recovery rate ≥92%) is used. It can restore its original shape within 5 seconds after being deformed by eyelid pressure, significantly improving the dynamic response ability of the lens to eyelid movement, avoiding positioning lag or failure due to insufficient material elasticity, and ensuring directional reliability during long-term wear.

[0026] 2. Significantly improve wearing comfort and reduce foreign body sensation:

[0027] 1. Optimize the edge structure to reduce eyelid friction: Through the dual-axis CNC cutting process, the thickness of the lens periphery is reduced from 0.2mm of the traditional prism vertical weight method to 0.13mm (0.13mm thickness of the upper edge and 0.15mm of the lower edge), combined with the 20° chamfer design with a width of 0.3mm on the upper edge, which effectively reduces the contact area and friction resistance between the eyelid and the edge of the lens. Clinical tests show that the foreign body sensation score of the 10-point system has been reduced from 4.8 points of traditional products to 2.8 points, a decrease of 42%, and no user has a moderate or above foreign body sensation (score>5 points), which significantly improves wearing comfort.

[0028] 2. Hydrophilic modification layer improves the distribution of the tear film: The thinning area and the groove area are treated with argon plasma to form a hydrophilic modification layer with a contact angle ≤ 30° (the contact angle after treatment is 25°), which enhances the adhesion and uniform distribution of the tear fluid, reduces the dryness caused by lens sliding and tear evaporation, and further enhances the wearing comfort.

[0029] III. New process reduces production costs and improves production feasibility:

[0030] 1. High-efficiency processing and forming technology simplifies the process: Five-axis precision machine tools are used for two-axis numerical control cutting. The gradient cutting of the thinning area is realized through the linkage of the rotating axis and the linear axis (accuracy

[0031] ±0.001 mm), and the single processing time ≤ 2 minutes. The efficiency is increased by 50% compared with the traditional laser marking method, and the equipment investment is reduced by 70%. The thermoforming curing process is carried out by molding at 130 °C and 5 MPa for 5 minutes to shape the edge groove and the asymmetric structure, and the material structure retention rate ≥ 98%. It avoids the problem of heavy edge processing in the traditional prism plumb method. The production cost of a single lens is reduced from $5 to $2, a decrease of 60%.

[0032] 2. High finished product rate and quality stability: The smooth edge treatment process after thermoforming reduces the lens breakage rate from 8% of the traditional process to 1.5%. Combining the directional modification of the plasma treatment on the local area (avoiding the strength reduction caused by the full-surface treatment) ensures the long-term stability of the mechanical properties and positioning structure of the lens, meeting the high-precision requirements of industrial production.

[0033] IV. Technical extension and application expansion:

[0034] By introducing intelligent responsive variants of temperature-sensitive materials (such as poly(N-isopropylacrylamide)), a personalized adaptation system based on corneal topography, and an optical coherence tomography quality inspection device, the present invention can further adapt to the eyelid pressure characteristics, corneal shape differences of different users, and the quality control requirements of mass production, forming a complete technical system from design, manufacturing to detection, and promoting the development of the colored contact lens industry towards precision and personalization.

[0035] Through the new structure of "vertical thinning area + asymmetric edge + micro-groove", shape memory hydrogel materials and high-efficiency processing technology, the present invention has achieved a breakthrough improvement in positioning accuracy (deviation angle ≤ 3°), wearing comfort (the foreign body sensation is reduced by 42%), and production cost (a decrease of 60%), providing an innovative and practical solution for the orientation technology of colored contact lenses, and having significant industrial application value and technological foresight. Brief Description of the Drawings

[0036] Figure 1Schematic diagram of the rear surface structure of the colored contact lens with an automatic orientation function and its preparation method in the present invention;

[0037] Figure 2 Schematic diagram of the cross-sectional structure of the colored contact lens with an automatic orientation function and its preparation method in the present invention;

[0038] Figure 3 Schematic diagram of the front surface structure of the colored contact lens with an automatic orientation function and its preparation method in the present invention. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] Please refer to Figures 1-3 , the present invention provides a technical solution:

[0041] Refer to Figures 1-3 as shown, an embodiment of a colored contact lens with an automatic orientation function and its preparation method:

[0042] I. New structural design:

[0043] Vertically thinned area:

[0044] Position and shape: A thickness gradient area is set in the 3-9 o'clock direction (horizontal orientation) of the lens, with a width accounting for 1 / 3 of the circumferential direction (corresponding to a 120° range), and radially covering from the center to 6.5 mm.

[0045] Key parameters: The center thickness is 0.08 mm, the thickness of the edge thinned area is 0.06 mm, the thinning amount is 0.02 mm (preferably 0.02 - 0.08 mm), and the thickness gradient change rate is 0.004 mm / mm (the thickness decreases by 0.004 mm per millimeter of radial distance).

[0046] Hydrodynamics-assisted structure:

[0047] Micro-groove array: 50 strip-shaped grooves are set at the upper and lower edges (vertical orientation) of the lens, with a depth of 100 μm (preferably 50 - 150 μm), a width of 200 μm (preferably 100 - 300 μm), and a spacing of 300 μm, and are evenly distributed in an array.

[0048] Asymmetric edge profile:

[0049] Upper edge: 20° chamfer (preferably 15-25°), chamfer width 0.3mm, edge thickness 0.13mm;

[0050] Lower edge: Maintaining a right-angle design, the edge thickness is 0.15mm, forming a 0.02mm thickness difference to enhance the directional torque when the eyelid is squeezed.

[0051] 2. Dynamic positioning mechanism:

[0052] Eyelid mechanical transmission: 0.3N / mm is applied to the thinning area when the upper eyelid blinks 2 The pressure causes the lens to produce a directional deformation torque of 0.5° / time, which causes the thinned area to align in the vertical direction (12-6 o'clock).

[0053] Tear film synergy: The edge grooves form a directional capillary effect, and the tear flow speed in the grooves reaches 0.1mm / s, guiding the lens to be stably positioned along the vertical axis (12-6 o'clock direction).

[0054] Material memory properties: It uses polyhydroxyethyl methacrylate (PHEMA) and polyurethane acrylate (PUA) copolymer hydrogel with a recovery rate of 95% (≥92%) and an elastic modulus of 0.8MPa (0.5-1.2MPa). It can recover to its original shape within 5 seconds after being deformed by eyelid pressure, ensuring long-term positioning stability.

[0055] 3. Production process:

[0056] Dual-axis CNC cutting: A 5-axis precision machine tool (accuracy ±0.001mm) is used to process hydrogel blanks with a diameter of 15.0mm and a thickness of 0.3mm. The gradient cutting of the thinning area is achieved through the linkage of the rotating axis and the linear axis. The cutting speed is 10mm / s and the single processing time is ≤2 minutes.

[0057] Plasma surface treatment: The thinned area and the groove area are treated with argon plasma (power 50W, time 30s, gas pressure 100Pa) to form a hydrophilic modified layer with a contact angle of 25° (≤30°), which improves tear adhesion and reduces lens slippage.

[0058] Thermoforming curing: Molding for 5 minutes at 130℃ (120-140℃) and 5MPa pressure to shape the edge grooves and asymmetric structures, with a material structure retention rate of ≥98%, avoiding the heavy edges of the traditional prism vertical weight method.

[0059] 4. Steps:

[0060] (I) Lens structure parameter comparison table:

[0061]

[0062]

[0063] (II) Preparation method steps:

[0064] 1. Biaxial numerical control cutting and forming:

[0065] Blank preparation: Fix the prepolymerized hydrogel blank (diameter 15.0 mm, thickness 0.3 mm, water content 45%) on a 5-axis machine tool, and set the radian of the front surface optical zone to 9.0 mm, the peripheral arc to 9.8 mm, and the back surface base arc to 8.8 mm.

[0066] Thinning area processing: In the 3-9 o'clock direction, with the center as the origin, perform gradient cutting on the radial 5.5-6.5 mm area to achieve a thinning amount of 0.02 mm, with a cutting accuracy of ±0.001 mm to ensure uniform thickness transition.

[0067] Edge treatment: Cut a 20° chamfer (width 0.3 mm) on the upper edge, keep the lower edge right-angled, and control the edge thickness within 0.13-0.15 mm to form an asymmetric structure.

[0068] Compared with the single thickening design of the traditional prism plumb method, the combination of the thinning area and the asymmetric edge reduces the peripheral thickness of the lens from 0.2 mm to 0.13 mm, and reduces the foreign body sensation score by 42%.

[0069] 2. Plasma surface treatment:

[0070] Treatment area: Only treat the thinning area and the upper and lower edge groove areas to avoid the reduction of material strength caused by full-surface modification.

[0071] Process parameters: Argon plasma (purity 99.99%), power 50 W, treatment time 30 s, air pressure 100 Pa, reducing the surface contact angle from 60° to 25°, improving the tear wettability, and reducing the lens rotation resistance.

[0072] The hydrophilic modified layer makes the tear film evenly distributed. Combining with the capillary effect of the groove, the lens stabilization time is shortened from 15 minutes of the traditional method to 6.2 minutes.

[0073] 3. Thermoforming and curing:

[0074] Molding and sizing: Place the cut lens in a high-precision ceramic mold, and hot-press it at 130°C and 5 MPa for 5 minutes to activate the shape memory property of the material and ensure the dimensional stability of the edge groove and the asymmetric structure (deviation ≤ ±1%).

[0075] Cooling and demolding: Demold after natural cooling to 25°C, and perform smooth edge treatment to remove burrs, reducing the breakage rate from 8% of the traditional process to 1.5%.

[0076] The thermoforming process enables the lens structure retention rate to reach 98%. Compared with the complex process of laser marking, the production cost is reduced by 60% (the cost per single lens is reduced to $2).

[0077] 4. Coloring and Post-treatment:

[0078] Coloring Process: In the coloring area (outer diameter 13.0 mm, inner diameter 6.0 mm), it is soaked and dyed with food-grade pigments, dyed at 50 °C for 10 minutes to ensure uniform color attachment, and the color fastness is ≥ 4 levels (no fading after being soaked in tear fluid for 72 hours).

[0079] Disinfection and Packaging: Soaked in 0.01% benzalkonium chloride physiological saline for 24 hours, irradiated and sterilized (25 kGy), and packaged in sterile aluminum-plastic packaging, with the microbial residue amount ≤ 10 CFU / sheet.

[0080] (3) Performance Test Data:

[0081] Positioning Accuracy Test:

[0082] Method: Worn on a simulated eye (corneal curvature 8.8 mm, diameter 12.0 mm), and the blinking process (15 times per minute) is recorded by a high-speed camera (100 fps).

[0083] Result: The rotation deviation angle is stable at 2.5° (≤ 3°) within 8 minutes, and the positioning accuracy is improved by 83% compared with traditional lenses (deviation angle ≥ 15°).

[0084] Clinical Comfort Test:

[0085] Subjects: 30 volunteers who have worn traditional prism gravity method lenses, with a wearing time of 8 hours.

[0086] Evaluation: Using a 10-point system for the foreign body sensation score, the average score of the lenses in this example is 2.8 points, which is 42% lower than that of traditional products (4.8 points), and no user has a foreign body sensation above moderate level (score > 5 points).

[0087] V. Summary:

[0088] Solving the pattern offset problem: Through the cooperation of the vertical thinning area (thinning amount 0.02 mm) and the asymmetric edge (20° chamfer), using the eyelid pressure to generate a directional torque (0.3 N / mm 2 ), combined with the capillary effect of the groove, the rotation deviation angle is controlled within 3° to ensure accurate pattern positioning.

[0089] Improving wearing comfort: The thinning area and the edge chamfer design reduce the peripheral thickness to 0.13 mm (0.2 mm by traditional methods), combined with the hydrophilic modification layer (contact angle 25°), reducing eyelid friction, and the foreign body sensation score is reduced by 42%, reaching the leading level in the industry.

[0090] Reduce production difficulty and cost: The dual-axis CNC cutting (accuracy ±0.001 mm) and thermoforming process (molding at 130 °C) simplify the process. Compared with the laser marking method, the equipment investment is reduced by 70%, the production cost of a single lens is reduced by 60%, and the breakage rate is reduced from 8% to 1.5%.

[0091] VI. Technical extension directions:

[0092] 1. Intelligent response type variants (combining temperature / pH sensitive materials):

[0093] Steps:

[0094] Modification of functional materials:

[0095] Material selection: Introduce the temperature-sensitive monomer poly(N-isopropylacrylamide) (PNIPAAm, LCST is about 32 °C) into the existing shape memory hydrogel (PHEMA / PUA copolymer), and prepare the composite hydrogel by free radical copolymerization. Control the content of PNIPAAm to be 15%-20% to make the material undergo reversible phase change within the eye temperature range (32-37 °C).

[0096] Performance regulation: By adjusting the concentration of the cross-linking agent (N,N'-methylenebisacrylamide) (0.5%-1.0%), adjust the elastic modulus of the material to 0.6-1.0 MPa, ensure that the elastic modulus is higher (0.8-1.0 MPa) below 32 °C and drops to 0.6-0.7 MPa at 37 °C to achieve temperature-responsive deformation.

[0097] Structural optimization design:

[0098] Embed a temperature-sensitive functional layer with a thickness of 0.01-0.03 mm in the thinning area (3-9 o'clock direction), and combine it with the surrounding ordinary hydrogel layer through a gradient cross-linking process to form a gradient distribution of elastic modulus (center area 0.8 MPa → edge area 0.6 MPa, at 37 °C).

[0099] Adjust the depth of the edge groove to 80-120 μm (dynamically adjust the capillary effect intensity with temperature change).

[0100] Verification of response mechanism:

[0101] In vitro simulation experiment: Place the lens in a constant temperature environment of 32 °C, 35 °C, and 37 °C, and measure the deformation angle of the thinning area when the eyelid is squeezed through a pressure sensor (deformation angle is 5° at 32 °C and 8° at 37 °C) to ensure that effective directional torque can be generated at different body temperatures (0.2-0.4 N / mm 2 )

[0102] Clinical test: Select people with different eyelid pressures (high pressure group: blinking pressure

[0103] ≥0.5 N / mm 2 , low - pressure group: blinking pressure ≤ 0.3 N / mm 2 ), verify the positioning stability of the lens when the body temperature changes (the rotation deviation angle is ≤ 3°).

[0104] 2. Personalized fitting system (parametric modeling based on corneal topography):

[0105] Steps:

[0106] Corneal data acquisition:

[0107] Use an optical coherence tomography scanner (OCT, resolution 5 μm) to obtain the user's corneal topography, record corneal curvature (8.5 - 9.5 mm), diameter (11.5 - 12.5 mm), astigmatism axis (0° - 180°), and corneal surface irregularity (RMS ≤ 10 μm).

[0108] Establish a three - dimensional model of the user's cornea and extract key parameters: corneal vertex curvature radius (K1, K2), corneal diameter (D), astigmatism degree (Cylinder).

[0109] Parametric model construction:

[0110] Based on finite element analysis (FEA), establish a lens - cornea coupled mechanical model, input corneal parameters and lens structure parameters (thinning zone thickness t = 0.02 - 0.08 mm, upper edge chamfer angle θ = 15° - 25°), and simulate the eyelid pressure distribution (pressure gradient 0.2 - 0.4 N / mm 2 ) and the lens rotation angle (target deviation angle ≤ 3°).

[0111] Develop an optimization algorithm (such as a genetic algorithm), with the goals of "minimizing the rotation deviation angle" and "minimizing the foreign body sensation score", to generate a personalized combination of structure parameters (for example: when the corneal curvature is 8.8 mm and the eyelid pressure is 0.3 N / mm 2 , it is recommended that t = 0.04 mm and θ = 20°).

[0112] Customized production implementation:

[0113] Import the optimized parameters into a 5 - axis CNC cutting machine, adjust the cutting path (the radial range of the thinning zone is 5.0 - 7.0 mm, and the chamfer tool angles of 15° / 20° / 25° are optional) to achieve single - lens customized processing (processing time ≤ 3 minutes per lens).

[0114] Establish a user database to record the correspondence between corneal parameters and lens structure parameters, supporting the rapid call of the design scheme during subsequent re - purchases.

[0115] 3. Production quality inspection device (optical coherence tomography positioning system):

[0116] Steps:

[0117] Hardware integration and calibration

[0118] Integrate a high-speed OCT module (scanning speed 50 kHz, axial resolution 10 μm), configure a rotary stage (accuracy ±0.1°), scan the lens 360°, and obtain the thickness distribution of the thinned area (radial area of 5.5 - 6.5 mm) and the three-dimensional topography of the edge groove (depth, width, spacing).

[0119] Establish a standard lens database, including the tolerance ranges of various parameters: thinning amount ±0.005 mm, groove depth ±5 μm, chamfer angle ±1°.

[0120] Online detection and feedback:

[0121] Automatically pick up the lens on the production line, position it to the detection station by the robotic arm, and the OCT system completes the full-lens scan within 10 seconds to generate a thickness cloud map and a groove contour map.

[0122] The image processing algorithm identifies defects: uneven thickness in the thinned area (deviation > ±0.01 mm), groove blockage (depth < 45 μm), or chamfer angle out of tolerance (> 25° or < 15°), and marks the unqualified products in real time (detection accuracy ≥ 99.5%).

[0123] Closed-loop production control:

[0124] Synchronize the detection data to the numerical control cutting machine control system, automatically adjust the cutting parameters (such as cutting speed in the thinned area ±2 mm / s, chamfer tool angle compensation ±0.5°), and achieve dynamic calibration during the production process.

[0125] Generate a quality report, record the parameter distribution of each batch of lenses (such as thinning amount mean 0.04 mm, standard deviation 0.003 mm), and ensure batch production consistency (CPK ≥ 1.33).

[0126] Intelligent responsive variant: By introducing a temperature-sensitive material (such as poly(N-isopropylacrylamide)) into the shape memory hydrogel, and utilizing the reversible phase change characteristics of the material within the eye temperature range (32 - 37 °C), automatic adjustment of the elastic modulus in the thinned area is achieved. When the eyelid pressure is high (such as in the scenario of frequent blinking), the eye temperature rises, triggering a decrease in the material modulus, increasing the deformation ability of the thinned area, and enhancing the directional torque; conversely, in the low-pressure scenario, the modulus increases to maintain the structural stability of the lens. This design can adapt to the eyelid movement characteristics of different users and further improve the environmental adaptability of the positioning system.

[0127] Personalized Adaptation System: Based on corneal topographic scan data, through parametric modeling and optimization algorithms, it realizes the customized design of lens structure parameters (thinning zone thickness 0.02 - 0.08 mm, upper edge chamfer 15° - 25°). The specific process includes: ① High-precision corneal data acquisition; ② Finite element simulation of eyelid pressure distribution and lens rotation behavior; ③ Genetic algorithm to optimize structure parameters and balance positioning accuracy and wearing comfort; ④ CNC cutting machine for personalized processing. This system solves the adaptability problem of the traditional "one-size-fits-all" lens design, especially suitable for users with irregular corneal morphology or high astigmatism.

[0128] Production Quality Inspection Device: Integrating optical coherence tomography (OCT) technology, it constructs an online inspection system to non-contact measure the key parameters of the lens: thinning zone thickness (accuracy ±0.001 mm), micro-groove depth (accuracy ±5 μm), and edge chamfer angle (accuracy ±1°). Through three-dimensional topography scanning and defect recognition algorithms, it monitors the production process in real time, automatically calibrates cutting parameters, ensures the consistency of mass production (CPK≥1.33), reduces the cost of manual inspection and the risk of missed inspection, and provides quality assurance for industrial production.

[0129] The automatic orientation colored contact lens and its preparation method provided in this embodiment, through the structural innovation of the vertical thinning zone, asymmetric edge, and micro-groove, combined with process improvements such as shape memory hydrogel materials and biaxial CNC cutting, systematically solve the core problems in traditional technologies: pattern rotation offset (deviation angle ≤3°), strong foreign body sensation (score reduction of 42%), and high production cost (cost reduction of 60%). Specifically:

[0130] The structural design realizes dynamic and precise positioning through the synergistic effect of eyelid mechanics conduction and tear film, avoiding the thick edges of the prism plumb method and the complex process of the laser marking method;

[0131] The innovation of materials and processes improves the comfort and production feasibility of the lens, reducing the peripheral thickness to 0.13 mm and the breakage rate from 8% to 1.5%;

[0132] The technical extension direction further expands the application scenarios: the intelligent response type variant adapts to personalized eyelid pressure, the personalized adaptation system solves the problem of corneal morphological differences, and the production quality inspection device ensures the accuracy of mass production, forming a complete technical system from design, manufacturing to inspection.

[0133] This solution meets the requirements of the patent law for the detail and repeatability of the specific implementation. The provided technical parameters and test data (such as rotation deviation angle ≤3°, stabilization time <8 min) are all verified through simulation and clinical trials, providing a practical technical solution for the precise positioning of colored contact lenses, and having significant industrial application value and technological foresight.

Claims

1. A colored contact lens with an automatic orientation function, comprising a lens body, characterized in that: a vertically thinned area is provided at the 3- 9 o'clock direction of the lens body, the width of the vertically thinned area accounts for 1 / 3 of the circumferential direction, radially covers from the center to 6.5 mm, and the edge thickness of the vertically thinned area is 0.02- 0.08 mm thinner than the center thickness; the upper edge of the lens body is chamfered at 15- 25°, and the lower edge is designed to be a right angle to form a thickness difference; micro-groove arrays are provided on the upper and lower edges of the lens body, the depth of the micro-grooves is 50-150 μm, the width is 100-300 μm, and they are evenly distributed in an array; the lens body is made of a copolymer hydrogel of hydroxyethyl polymethacrylate and polyurethane acrylate, with an elastic modulus of 0.5-1.2 MPa and a recovery rate ≥ 92%.

2. The colored contact lens with an automatic orientation function according to claim 1, wherein: The center thickness of the vertically thinned area is 0.06-0.12 mm, the thickness of the edge thinned area is the center thickness - 0.08 mm, and the thickness gradient change rate is 0.004 mm / mm.

3. The colored contact lens with an automatic orientation function according to claim 1, characterized in that: The chamfer width of the upper edge is 0.3 mm, the thickness of the upper edge is 0.13 mm, and the thickness of the lower edge is 0.15 mm, forming a thickness difference of 0.02 mm.

4. The colored contact lens with an automatic orientation function according to claim 1, characterized in that: The micro-groove array is a strip-shaped groove, the number is 50, and the spacing is 300 μm.

5. The colored contact lens with an automatic orientation function according to claim 1, characterized in that: The surface of the lens body is treated by plasma to form a hydrophilic modified layer, and the contact angle ≤ 30°.

6. A method for preparing a colored contact lens with an automatic orientation function, characterized in that, It includes the following steps: Biaxial CNC cutting and forming: Fix the pre-polymerized hydrogel blank on a 5-axis machine tool, and perform gradient cutting on the 5.5- 6.5 mm area in the radial direction at the 3-9 o'clock direction to form a vertically thinned area, and the thinning amount is 0.02- 0.08 mm; at the same time, cut the upper edge of the lens body at 15- 25° chamfer, and the lower edge remains a right angle to form an asymmetric edge structure; Plasma surface treatment: Perform argon plasma treatment on the thinned area and the upper and lower edge groove areas, with a power of 50-100 W, a treatment time of 20-40 s, and a gas pressure of 80- 120 Pa to form a hydrophilic modified layer with a contact angle ≤ 30°; Thermoforming and curing: Place the cut lens in a ceramic mold, and perform die pressing at 120-140 °C and a pressure of 4-6 MPa for 3- 7 minutes to shape the edge grooves and the asymmetric structure, and the material structure retention rate ≥ 98%; Coloring and post-treatment: Immerse and dye with food-grade pigments in the coloring area, the temperature is 40-60 °C, the time is 8-12 minutes, and then disinfect and package.

7. The manufacturing method of a colored contact lens with an automatic orientation function as claimed in claim 6, wherein: In the biaxial CNC cutting and forming step, the diameter of the hydrogel blank is 13.0- 14.5 mm, the thickness is 0.2-0.4 mm, the cutting accuracy is ±0.001 mm, and the cutting speed is 8-12 mm / s.

8. The preparation method of a colored contact lens with an automatic orientation function as described in claim 6, characterized in that: In the plasma surface treatment step, the purity of argon ≥ 99.99%, and the surface contact angle after treatment drops from 60° to 25-30°.

9. The preparation method of a colored contact lens with an automatic orientation function according to claim 6, characterized in that: In the thermoforming and curing step, the cooling and demolding temperature is 20- 30 °C, and the edge is smoothly treated after demolding, and the breakage rate ≤ 1.5%.

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