Lens and lens custom design method

Abstract

The application discloses a lens and a lens customized design method, belongs to the field of ophthalmic surgical devices, is used for the treatment of myopia, realizes the compensation of ocular refraction, processes the lens based on the target angle resolution scattering distribution and the target surface power spectral density of the lens, realizes the accurate quantification and design optimization of the scattering performance, determines the target optical structure parameters of the lens based on the target optical performance parameters, realizes the quantitative correlation between the microstructure parameters of the lens and the optical performance, and improves the design reliability. The target angle resolution scattering distribution of the processed lens conforms to ideal Lambert scattering characteristics, effectively homogenizes the retinal illumination distribution, reduces the local light intensity peak value, thereby reduces the image signal contrast, maintains high light transmittance while realizing specific light scattering control, significantly improves the visual comfort, treats myopia, relieves asthenopia symptoms, and can also adjust the scattering characteristic parameters according to different user requirements.

Description

Technical Field

[0001] This invention relates to the field of ophthalmic surgical devices for the treatment of myopia and to achieve refractive compensation of the eye, and particularly to a lens for myopia control and a method for custom designing the lens. Background Technology

[0002] Myopia is a common vision problem, with its incidence rising year by year, especially among children. The main characteristic of myopia is an elongated eyeball, which prevents distant objects from forming a clear image on the retina. Currently, methods for myopia control mainly include optical intervention, pharmacological intervention, and behavioral intervention. In the field of optical intervention, traditional monofocal lenses can only correct visual acuity and cannot effectively slow the progression of myopia.

[0003] Defocus eyeglasses and orthokeratology lenses, as the most effective means of myopia control currently available, each have significant limitations. The main drawback of defocus eyeglasses is that their myopia control effect may be slightly inferior to orthokeratology lenses, and to achieve optimal results, children need to wear them all day, requiring high adherence. Furthermore, the peripheral optical design of the lenses may cause wearers to experience slight peripheral visual blur or distortion initially. Defocus soft contact lenses, like other contact lenses, carry the risk of corneal infection and complications, requiring wearers and parents to have good hygiene habits and care skills. While orthokeratology lenses are widely recognized for their excellent myopia control effect, their drawbacks are more significant: they require users to perform complex and strict daily cleaning and care; improper care greatly increases the risk of corneal infection, which is their main challenge. Secondly, the reshaping effect is completely reversible, requiring consistent nightly wear, and their fitting requirements and costs are relatively high, making them unsuitable for children with all degrees of myopia or corneal conditions. In summary, both methods require users or parents to invest a lot of time, energy, or money, and cannot completely cure myopia, but only slow down its progression. Both also carry certain potential risks of eye complications and require professional and continuous monitoring.

[0004] Recent studies have found that intervening in the imaging quality of the peripheral retina, such as by reducing the contrast of the peripheral visual field, can slow axial elongation and thus control myopia progression. The lenses used include a central clear visual zone and a peripheral treatment zone, ensuring both the wearer's daily visual needs and achieving myopia control. This design is suitable for both spectacle and contact lenses, and is especially suitable for long-term wear by children and adolescents. Existing Sightglass Vision-Nikon DOT lenses consist of a central clear aperture (5mm in diameter) surrounded by thousands of micro-scattering centers distributed throughout the lens surface. The scattering center design focuses on reducing contrast, using chemical etching or nanoimprinting to fabricate the microstructure. However, characterizing the lens's scattering ability relies on a single haze index, which does not characterize the lens's specific physical processing structure. Furthermore, the distribution of the microstructures or microlenses on the lens is a fixed structure, exhibiting a geometric consistency at least in one direction. This results in insufficient resistance to visual disturbances, a short-lived myopia control effect, and a decline in effectiveness once the user adapts. Additionally, it cannot be customized to meet the user's specific needs. Summary of the Invention

[0005] In view of the above problems, this invention proposes a lens and a lens customization design method to achieve precise quantification and design optimization of scattering performance, quantitative correlation between lens surface microstructure parameters and optical performance, improve design reliability, and enable personalized customization according to the actual needs of users.

[0006] One technical solution of the present invention is: a lens customization design method, comprising:

[0007] The target optical performance parameters of the lens are determined based on the eye parameters corresponding to the lens, and the target optical performance parameters include the target angular-resolved scattering distribution and the target surface power spectral density of the lens;

[0008] The target optical structure parameters of the lens are determined based on the target optical performance parameters, and the target optical structure parameters of the lens include at least the target root mean square roughness of the lens.

[0009] Based on the target optical structure parameters and the target optical performance parameters, processing parameters are set, and the lens is processed so that the measured surface power spectral density of the lens is within the set target surface power spectral density range, and the measured angle-resolved scattering distribution of the lens conforms to an ideal Lambertian distribution.

[0010] Furthermore, the target optical performance parameters of the lens are determined based on the user's eye parameters corresponding to the lens, including:

[0011] The target total scattering integral of the lens is determined based on the user's eye parameters corresponding to the lens. The target total scattering integral of the lens is the ratio of the light power scattered by the lens to the total incident light power.

[0012] The target angular resolution scattering distribution of the lens is determined based on the total target scattering integral.

[0013] The target surface power spectral density of the lens is determined based on the target angle-resolved scattering distribution.

[0014] Furthermore, determining the target total scattering integral of the lens based on the user's corresponding ocular parameters includes:

[0015] The target light intensity attenuation rate of the lens is determined based on the eye parameters.

[0016] The total target scattering integral of the lens is determined based on the target light intensity attenuation rate.

[0017] Furthermore, determining the target angular-resolved scattering distribution of the lens based on the total target scattering integral includes:

[0018] Based on the total scattering integral of the target, the angular resolution scattering distribution of the lens conforms to the ideal Lambertian scattering characteristics;

[0019] The target angular resolution scattering distribution of the lens is as follows:

[0020] ARS target (θ s ) = (TIS target / π) cos(θ s );

[0021] The ARS target The TIS is a target angle-resolved scattering distribution for the lens. target θ is the total target scattering integral of the lens. s The scattering angle represents the angle between the scattering direction and the normal to the mirror surface of the lens.

[0022] Furthermore, determining the target surface power spectral density of the lens based on the target angle-resolved scattering distribution includes:

[0023] The correlation between the target's angularly resolved scattering distribution and the target's surface power spectral density is established, expressed as: ;

[0024] The scattering angular domain is mapped to the surface spatial frequency domain based on the grating equation, which is: ;

[0025] The expression for the target surface power spectral density of the lens is derived as follows: ;

[0026] Where λ is the wavelength of the incident light, and θ s Let θ be the scattering angle. i Where is the incident angle, Q is the optical factor, which is related to the refractive index and polarization state of the material, f is the surface spatial frequency, and K is the normalization constant, which is determined by the total scattering integral of the target.

[0027] Furthermore, determining the target optical structure parameters of the lens based on the target optical performance parameters includes:

[0028] Integrating the power spectral density of the target surface over the effective bandwidth yields the root mean square roughness of the target:

[0029] ;

[0030] in, and These represent the minimum and maximum values ​​of the effective bandwidth.

[0031] Furthermore, based on the target optical structure parameters and the target optical performance parameters, processing parameters are set to process the lens so that the measured surface power spectral density of the lens is within the set target surface power spectral density range, including:

[0032] The processing parameters are set based on the target root mean square roughness of the lens, and the lens is processed.

[0033] The processed lens was tested to measure the actual surface power spectral density of the processed lens;

[0034] If the measured surface power spectral density is outside the set target surface power spectral density range, adjust the processing parameters and / or the target surface power spectral density, repeat the processing and testing;

[0035] If the measured surface power spectral density is within the set target surface power spectral density range, the lens processing is complete.

[0036] Furthermore, the test also includes optical verification, including:

[0037] Measure whether the angle-resolved scattering distribution of the lens conforms to a Lambertian distribution;

[0038] The total scattering integral is obtained by integrating the measured angle-resolved scattering distribution, and the obtained total scattering integral is verified to conform to the target total scattering integral.

[0039] Furthermore, the ideal Lambertian scattering characteristics include:

[0040] The lens surface has a completely random and isotropic surface roughness and a randomly arranged microstructure;

[0041] The randomly arranged microstructures include:

[0042] The microstructure controlled by extremely low frequency is determined by the overall macroscopic position of the micro-dots;

[0043] A low-to-medium frequency control structure determined by the random position of micro-points;

[0044] A mid-to-high frequency control structure determined by the random depth and / or shape of micro-dots.

[0045] Another technical solution of the present invention provides a lens, which is manufactured using the aforementioned lens customization design method, and the angular resolution scattering distribution of the lens conforms to the ideal Lambertian scattering characteristics.

[0046] The lens and lens customization design method provided by this invention process the lens based on the target angle-resolved scattering distribution and target surface power spectral density, achieving precise quantification and design optimization of scattering performance. Based on the target optical performance parameters, the target optical structure parameters of the lens are determined, realizing a quantitative correlation between the lens's microstructure parameters and optical performance, thus improving design reliability. The processed lens effectively homogenizes the retinal illuminance distribution, reduces local light intensity peaks, thereby reducing image signal contrast, maintaining high transmittance while achieving specific light scattering control, significantly improving visual comfort, alleviating eye fatigue symptoms, and allowing for adjustment of scattering characteristic parameters to meet different user needs.

[0047] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are given below. Attached Figure Description

[0048] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0049] Figure 1 A detailed flowchart of the lens customization design method provided in an embodiment of the present invention is shown.

[0050] Figure 2 A schematic diagram of surface scattering of the lens of the present invention is shown.

[0051] Figure 3A schematic diagram of the laser optical path used in the processing according to the present invention is shown.

[0052] Figure 4 The diagram shows a random distribution of light scattering centers obtained by laser processing according to the present invention.

[0053] Figure 5 An enlarged view of the light scattering center obtained by laser processing according to the present invention is shown.

[0054] Figure 6 A schematic diagram of the conical structure formed by a single Gaussian spot processing according to the present invention is shown. Detailed Implementation

[0055] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0056] Existing myopia control lenses rely on a single indicator to characterize their scattering ability, failing to represent the lens's specific physical processing structure. Furthermore, the distribution of microstructures or microlenses on the lens depends on a fixed program, resulting in a fixed structure with at least a consistent geometric shape in one direction or a consistent spatial distribution, thus forming a specific artificial pattern. This leads to minimal visual variation during fixation, resulting in insufficient stimulation of visual disturbances and a short-lived myopia control effect. Once the user's nervous system adapts, the control effect diminishes. Moreover, because they are generated according to a fixed program and are independent of the user's specific parameters, they cannot be customized to meet the user's actual needs.

[0057] To address the aforementioned issues, the technical solution of this invention provides a lens and a lens customization design method. By processing the lens based on its target angle-resolved scattering distribution and target surface power spectral density, it achieves precise quantification and design optimization of scattering performance. Based on the target optical performance parameters, it determines the target optical structure parameters of the lens, realizing a quantitative correlation between the lens's microstructure parameters and optical performance, thus improving design reliability. The processed lens effectively homogenizes the retinal illuminance distribution, reduces local light intensity peaks, thereby reducing image signal contrast. While maintaining high transmittance, it achieves specific light scattering control, significantly improving visual comfort, alleviating eye fatigue symptoms, and allowing for adjustment of scattering characteristic parameters to meet different user needs. In the technical solution of this invention, a specific target angle-resolved scattering distribution (ARS) is designed for the eye habits and myopia development trends of adolescents. The target gently and uniformly reduces the light intensity entering the eye at all angles throughout the entire field of view. This is equivalent to adding a slight, uniform "background noise" to the visual signal, thereby reducing the overall image contrast.

[0058] Based on the above technical background and ideas, the specific implementation of the present invention includes the following: Example 1:

[0059] refer to Figure 1 This embodiment provides a lens customization design method, the customization design method including:

[0060] S1: Determine the target optical performance parameters of the lens based on the eye parameters corresponding to the lens, wherein the target optical performance parameters include the target angle-resolved scattering distribution and the target surface power spectral density of the lens;

[0061] S2: Determine the target optical structure parameters of the lens based on the target optical performance parameters, wherein the target optical structure parameters of the lens include at least the target root mean square roughness of the lens;

[0062] S3: Based on the target optical structure parameters and the target optical performance parameters, set the processing parameters and process the lens so that the measured surface power spectral density of the lens is within the set target surface power spectral density range, and the measured angle-resolved scattering distribution of the lens conforms to the ideal Lambertian distribution.

[0063] like Figure 2 As shown, the optical performance target of the lens is quantified into two core parameters: Total Integrated Scattering (TIS) and Angle-Resolved Scattering (ARS). The Angle-Resolved Scattering is defined as:

[0064] (1)

[0065] in, Represents the scattering power per unit solid angle. Represents a solid angle (unit: steradian, sr). A solid angle is an angle in three-dimensional space, used to measure the size of the space covered by a cone, while a unit solid angle specifically refers to... The solid angle at 1sr. Pi represents the incident power, θ i P represents the angle of incidence. s Represents the scattering power, θ s P represents the scattering angle. r Represents the reflected power, θ r Represents the reflection angle; θ s Used to quantify the directional distribution of scattered light, it is directly related to the spatial frequency of surface roughness and is a core variable connecting light scattering measurements and surface topography statistics (such as surface power spectral density PSD). The total scattering integral (TIS) is defined as the ratio of the scattered light power to the total incident light power, and its target value is directly determined by the system-level light intensity attenuation requirements.

[0066] In step S1, determining the target optical performance parameters of the lens based on the user's corresponding eye parameters includes:

[0067] S11: Determine the target total scattering integral of the lens based on the user's eye parameters corresponding to the lens. The target total scattering integral of the lens is the ratio of the light power scattered by the lens to the total incident light power.

[0068] S12: Determine the target angular resolution scattering distribution of the lens based on the total target scattering integral;

[0069] S13: Determine the target surface power spectral density of the lens based on the target angle-resolved scattering distribution.

[0070] In step S11, determining the target total scattering integral of the lens based on the user's eye parameters corresponding to the lens includes: determining the target light intensity attenuation rate of the lens based on the eye parameters; and determining the target total scattering integral of the lens based on the target light intensity attenuation rate.

[0071] In this embodiment, the eye parameters corresponding to the lens can be direct parameters such as pupil diameter and interpupillary distance, or other parameters obtained based on medical examinations and diagnoses. The target light intensity attenuation rate of the lens is determined based on these parameters. For example, setting the target light intensity attenuation rate to 20% achieves an overall 20% reduction in transmitted light intensity. Ignoring lens absorption, the total scattering integral (TIS) target value needs to be set to approximately 0.2 (i.e., 20%). This means that 20% of the incident light energy will deviate from the mirror's transmission direction due to scattering and will no longer participate in forming a clear image point, thus directly contributing to the reduction in overall image contrast. Without affecting normal vision, the actual range for setting the target light intensity attenuation rate can be between 10% and 50%.

[0072] In step S12, determining the target angular-resolved scattering distribution of the lens based on the total target scattering integral includes:

[0073] Based on the total scattering integral of the target, the angular resolution scattering distribution of the lens conforms to the ideal Lambertian scattering characteristics.

[0074] This invention requires that the ARS distribution of the lens approximates the ideal Lambertian scattering characteristics. Optically, an ideal Lambertian scattering property has an ARS that follows the rule ARS(θ). s )∝cos(θ s The distribution pattern of ) where θ s Let θ be the angle between the scattering direction and the normal to the lens surface. This distribution characteristic ensures that the radiance of the scattered light is uniformly distributed within the hemispherical space, and its apparent brightness remains consistent from any viewing angle. This highly diffuse light scattering superimposes a broad and uniform background light curtain on the retinal image plane, thereby globally and smoothly reducing the modulation contrast of the image without introducing visual interference. To produce uniform Lambertian scattering, the power spectrum of the surface roughness needs to maintain a constant value (i.e., exhibiting a 'white noise' spectrum) over a very wide frequency range (from low frequencies below the reciprocal of the incident light wavelength to high frequencies above it). If the power spectrum drops in the high-frequency region, it will lead to the lack of large-angle scattering, thus deviating from the ideal Lambertian distribution.

[0075] To achieve a "uniform and gentle" visual attenuation effect, the target angle-resolved scattering distribution (ARS) in this embodiment should be set to an ideal Lambertian scattering pattern, ensuring that the scattered light is uniformly distributed within the hemispherical space, resulting in consistent brightness from any viewing angle. The target angle-resolved scattering distribution function of the lens is:

[0076] ARS target (θ s ) = (TIS target / π) cos(θ s (2)

[0077] The ARS target The TIS is a target angle-resolved scattering distribution for the lens. target θ is the total target scattering integral of the lens. s The scattering angle represents the angle between the scattering direction and the normal to the mirror surface of the lens.

[0078] In step S13, determining the target surface power spectral density of the lens based on the target angle-resolved scattering distribution includes:

[0079] The correlation between the target's angularly resolved scattering distribution and the target's surface power spectral density is established, expressed as:

[0080] (3)

[0081] Where λ is the wavelength of the incident light, and θ s Let θ be the scattering angle. i θ is the incident angle, Q is the optical factor, which is related to the refractive index and polarization state of the material, and f is the surface spatial frequency.

[0082] The above expression is based on the generalized Harvey-Shack (GHS) theory, which shows that the surface scattering properties of a mirror (such as the angle-resolved scattering distribution (ARS)) are directly related to the surface power spectral density (PSD). At a specific angle (θ)... s The angle-resolved scattering distribution intensity (ARS) under the surface topography is directly determined by the surface power spectral density (PSD) at a specific spatial frequency (f).

[0083] Surface power spectral density (PSD) is based on Fourier analysis. Within a specified spatial frequency domain, it transforms the undulations of surface topography into the intensity spectral distribution of high, medium, and low frequency topography components. This "energy distribution" analysis based on spatial frequency domain is often used to predict the scattering properties of optical surfaces. Increasing the high-frequency components of the PSD helps enhance large-angle scattering. Specifically, the ARS of a randomly rough surface can be simulated using GHS theory, and the measured ARS values ​​can be combined to guide the optimization of lens surface structure.

[0084] The scattering angular domain is mapped to the surface spatial frequency domain based on the grating equation, which is:

[0085] (4);

[0086] Scattering angle θ sA specific scattering angle θ corresponds one-to-one with the surface spatial frequency f through the grating equation. s This directly corresponds to a specific surface spatial frequency f. A mapping is established using the grating equation: at normal incidence (θ... i Under the condition of 0), the scattering angle domain is mapped to the surface spatial frequency domain using the grating equation:

[0087] (5);

[0088] The physical relationship between the target ARS and the target surface power spectral density (PSD) is established, and then... The expression for the target surface power spectral density of the lens is obtained as follows:

[0089] (6);

[0090] Wherein, K is a normalization constant, determined by the total scattering integral of the target.

[0091] In step S2, the target optical structure parameters of the lens are determined based on the target optical performance parameters, including:

[0092] The power spectral density of the target surface within the effective bandwidth [f min , f max Integrating within the range yields the target root mean square roughness (RMS roughness), providing a control target for the overall roughness of the manufacturing process. The specific formula is as follows:

[0093] (7);

[0094] Among them, f min and f max For the minimum and maximum values ​​of the effective bandwidth, in calculating surface roughness, the effective bandwidth refers to the spatial frequency range considered when measuring or analyzing the power spectral density (PSD) curve of the target surface. The effective bandwidth defines the spatial frequency range within which surface defects of which scales are included in the RMS roughness calculation. f < f min The structure: usually considered as form error or not measured. f>f max The structure of the target is usually microscopic roughness at the atomic level or unresolved by measuring equipment. The root mean square roughness of the target is related to the surface scattering performance of the optical material and determines the scattering ability of the material.

[0095] In step S3, processing parameters are set based on the target optical structure parameters and the target optical performance parameters, and the lens is processed to ensure that the measured surface power spectral density of the lens is within the set target surface power spectral density range, including:

[0096] S31: Based on the target root mean square roughness of the lens, set the processing parameters and process the lens;

[0097] S32: Test the processed lens to measure the actual surface power spectral density of the processed lens;

[0098] S321: If the measured surface power spectral density is outside the set target surface power spectral density range, adjust the processing parameters or the target surface power spectral density, repeat the processing and testing; in this step, under normal circumstances, it is only necessary to adjust the processing parameters to be close to the required target value, and the target surface power spectral density, as the ideal result, generally does not need to be adjusted;

[0099] S322: If the measured surface power spectral density is within the set target surface power spectral density range, the lens processing is complete.

[0100] In step S31, based on the target surface power spectral density and σ target Select and optimize surface treatment processes. For example... Figure 4 The laser processing shown allows the measured surface power spectral density of the processed lens to approximate the target surface power spectral density to the maximum extent.

[0101] To achieve the aforementioned ideal Lambertian scattering characteristics, the ideal Lambertian lens fabricated in this embodiment has a completely random and isotropic surface roughness and randomly arranged microstructures, capable of uniformly redistributing light to all hemispherical directions. The number (density) and coverage area (fill rate) of the microstructures on the lens directly determine the magnitude of contrast reduction. This embodiment achieves this through a random Fourier synthesis method, which generates the time domain (surface height) by controlling the random phase in the frequency domain (surface power spectral density PSD). The power spectral density PSD shape in different spatial frequency ranges is controlled by three levels of microstructure parameters, thereby achieving the target scattering characteristics. The randomly arranged microstructures include:

[0102] (i) The microstructure controlled by the overall macroscopic position of micro-points. Specifically, the macroscopic position of more than 20,000 (25,000-30,000 points / piece) micro-points controls the ultra-low frequency region (f<0.005cyc / μm), which affects the total RMS roughness and the overall scattering energy distribution.

[0103] (ii) The low-to-mid frequency control structure determined by the random position of micro-points, in the low-to-mid frequency range (0.005~0.05cyc / μm), is determined by the random position of micro-points. The surface power spectral density (PSD) in this frequency band is kept flat by the irregular overlap and boundaries between substructures, thereby achieving uniformity of small-angle scattering.

[0104] (iii) The mid-to-high frequency control structure determined by the random depth and / or shape of the micro-dots, in the mid-to-high frequency region (f>0.05cyc / μm), is controlled by the random depth or shape of the micro-dots. These micron-level and submicron-level random slope changes generate high-amplitude surface power spectral density (PSD), which causes the angle-resolved scattering distribution (ARS) to rise sharply at large angles, ultimately achieving a Lambertian-like scattering effect.

[0105] At the same time, such as Figure 4 As shown, the light scattering center obtained by laser processing is formed by the superposition of multiple adjacent or intersecting laser spots (e.g. Figure 5 As shown), this superposition or irregular arrangement inevitably produces a large number of local micro-sloping surfaces. These micro-sloping surfaces, with random orientations, are the real reason for achieving wide-angle scattering. Furthermore, the result of a single Gaussian spot processing is a conical structure approximating the slope (as shown). Figure 6 As shown in the figure, a uniform change in surface depth can be achieved.

[0106] In step S3 above, the laser processing parameter setting procedure can specifically be the following code:

[0107] print(f"Size of the generated topography image: {Z.shape}")

[0108] print(f"Minimum depth (maximum depression): {np.min(Z):.4f} micrometers")

[0109] print(f"Maximum height (overlapping boundary): {np.max(Z):.4f} micrometers")

[0110] import numpy as np

[0111] import math

[0112] def generate_poisson_disk_sampling(R_lens, D_micro, N_target):

[0113] """

[0114] Generate approximately N_target points with a uniform and aperiodic distribution within the circular region.

[0115] # Args:

[0116] R_lens (float): Lens radius (e.g., 35.0 mm)

[0117] D_micro (float): Micro-dot diameter / minimum spacing (e.g., 0.2 mm)

[0118] N_target (int): The number of target points (e.g., 20000)

[0119] Returns:

[0120] np.ndarray: An N x 2 matrix containing the (X, Y) coordinates of points.

[0121] """

[0122] # 1. Parameter Initialization

[0123] d_min = D_micro # Minimum spacing is set to the diameter of the micro-dots

[0124] # Estimate the number of iterations and candidate points based on the target number of points and minimum spacing.

[0125] # This is a simplified version; actual Poisson disk sampling is more complex, so an efficient approximation is used here.

[0126] points = []

[0127] # 2. Determine the initial point

[0128] # Randomly select the first point, ensuring it is within the lens area.

[0129] initial_point = np.array([np.random.uniform(-R_lens, R_lens),

[0130] np.random.uniform(-R_lens, R_lens)])

[0131] while np.sum(initial_point 2) > R_lens 2: # Ensure within the circular area

[0132] initial_point = np.array([np.random.uniform(-R_lens, R_lens),

[0133] np.random.uniform(-R_lens, R_lens)])

[0134] points.append(initial_point)

[0135] # 3. Simplify the iterative process (Approximation)

[0136] # Use random addition and rejection to reach the target number.

[0137] max_attempts = N_target 5 # Prevent infinite loops

[0138] attempts_count = 0

[0139] while len(points) < N_target and attempts_count < max_attempts:

[0140] # a. Randomly select an accepted point (acceleration)

[0141] idx = np.random.randint(0, len(points))

[0142] ref_point = points[idx]

[0143] # b. In the annular region [d_min, 2 [d_min] Randomly generate a candidate point

[0144] # Distance d is random, angle theta is random

[0145] distance = np.random.uniform(d_min, 2 d_min)

[0146] angle = np.random.uniform(0, 2 np.pi)

[0147] cand_point = ref_point + np.array([distance np.cos(angle),

[0148] distance np.sin(angle)])

[0149] # c. Check validity

[0150] # 1) Check if it is within the circular area

[0151] if np.sum(cand_point 2) > R_lens 2:

[0152] attempts_count += 1

[0153] continue

[0154] # 2) Check if the minimum spacing requirement is met.

[0155] is_valid = True

[0156] For p in points:

[0157] dist_sq = np.sum((cand_point - p) 2)

[0158] if dist_sq < d_min 2:

[0159] is_valid = False

[0160] break

[0161] if is_valid:

[0162] points.append(cand_point)

[0163] attempts_count += 1

[0164] return np.array(points)

[0165] # --- Example Run ---

[0166] R_LENS = 35.0 # 35 mm

[0167] D_MICRO = 0.20 # 0.2 mm (200 um)

[0168] N_TARGET = 20000

[0169] # Generate the center coordinates of 20,000 micro-points

[0170] micro_centers = generate_poisson_disk_sampling(R_LENS, D_MICRO, N_TARGET)

[0171] print(f"Target points: {N_TARGET}")

[0172] print(f"Actual number of points generated: {len(micro_centers)}")

[0173] print("Coordinates have been generated and can be used for the next step of micro-point topology overlay.").

[0174] The algorithm for single micro-point structure planning in step 3 above is specifically shown in the following code:

[0175] import numpy as np

[0176] import math

[0177] # --- 1. Define core design parameters ---

[0178] D_MICRO = 200.0 # Diameter of a single microdot (micrometers)

[0179] N_SUB_POINTS = 28 # Number of substructures (number of laser points)

[0180] MAX_DEPTH = 2.5 # Maximum machining depth (micrometers)

[0181] GRID_SIZE = 1024 # The pixel resolution of the generated topography image (e.g., 1024x1024)

[0182] PIXEL_SIZE = D_MICRO / GRID_SIZE # Physical size of a single pixel (micrometers / pixel)

[0183] # --- 2. Initialize the height matrix Z(x, y) ---

[0184] # Initialize a matrix of all zeros to represent a smooth surface.

[0185] Z = np.zeros((GRID_SIZE, GRID_SIZE))

[0186] # --- 3. Generate data for random micro-points ---

[0187] # Iteratively generate each microdot

[0188] for i in range(N_SUB_POINTS):

[0189] # a. Random location (approximate to Poisson distribution)

[0190] # Set the center in the micro-point region (-D / 2 to D / 2)

[0191] # Randomly generate the center coordinates (cx, cy) of a micro-point

[0192] cx = np.random.uniform(-D_MICRO / 2.0, D_MICRO / 2.0)

[0193] cy = np.random.uniform(-D_MICRO / 2.0, D_MICRO / 2.0)

[0194] # b. Random Depth (Modulation)

[0195] # Depth varies randomly between [0.5, MAX_DEPTH].

[0196] H_k = np.random.uniform(0.5, MAX_DEPTH)

[0197] # c. Random micro-dot size (optional optimization)

[0198] # The diameter of the microdot varies randomly between [25, 50] micrometers.

[0199] D_sub = np.random.uniform(25.0, 50.0)

[0200] R_sub = D_sub / 2.0

[0201] # d. Calculate the contribution of the micro-point to the Z matrix (using a Gaussian / conical shape to simulate the laser point)

[0202] # Traverse each pixel of the Z matrix

[0203] for r in range(GRID_SIZE):

[0204] for c in range(GRID_SIZE):

[0205] # Convert pixel coordinates (r, c) to physical coordinates (x, y)

[0206] x_phys = (c - GRID_SIZE / 2.0) PIXEL_SIZE

[0207] y_phys = (r - GRID_SIZE / 2.0) PIXEL_SIZE

[0208] # Calculate the distance from the pixel to the center of the microdot

[0209] dist = math.sqrt((x_phys - cx) 2 + (y_phys - cy) 2)

[0210] # --- Micro-dot shape function ---

[0211] # Using Gaussian functions as micro-point topography (simulating diffused laser ablation)

[0212] if dist < 2.0 R_sub: # Limit the calculation range

[0213] # Gaussian function: simulates smooth depressions, but achieves coarseness through random superposition.

[0214] # Intensity (height) decreases with distance

[0215] shape_val = H_k math.exp(-(dist 2) / (2.0 R_sub 2))

[0216] # Overlay: Take the maximum depression value in the overlay morphology (or simply sum them, depending on the process).

[0217] # Note: If the laser spot is "etching" or "removing" material, then a negative value should be used to represent the depth.

[0218] # Positive values ​​are used here to represent the range of height change.

[0219] Z[r, c] = Z[r, c] + shape_val # Simple shape superposition (summation)

[0220] # --- 4. Final Normalization and Output ---

[0221] # Convert all shapes to concave (negative value)

[0222] Z = -Z

[0223] # Ensure the final shape's depth does not exceed MAX_DEPTH

[0224] if np.min(Z) < -MAX_DEPTH:

[0225] Z = Z (-MAX_DEPTH / np.min(Z))

[0226] # --- 5. Exporting Data (Example) ---

[0227] The Z matrix now contains a satisfactory surface height map of a 200µm microstructure with random roughness.

[0228] # Z_output = Z.flatten()

[0229] # np.savetxt('microstructure_height_map.txt', Z_output) .

[0230] The dot-diffusion anti-myopia lens in this embodiment uses a large number of light-scattering micro-dots integrated into the lens to gently diffuse the incident light, thereby slightly reducing the effective light contrast reaching the retina. This simulates a low-stimulation visual environment, weakens the high-contrast signal that is thought to stimulate the progressive elongation of the eye axis, and achieves the purpose of delaying the progression of axial myopia while ensuring clear central vision.

[0231] In terms of macroscopic environmental factors, soft, uniform light intensity is believed to reduce eye strain by stabilizing retinal signal transmission and alleviating accommodative and convergence stress on the eyes. Image contrast measures the degree of brightness difference in an image and is a key factor affecting retinal perception and signal transmission; while background noise refers to random interference that affects signal clarity. Both factors work together to affect the signal-to-noise ratio, determining the quality of visual information reception. Non-uniform and spatially frequency-dependent: Contrast reduction is not uniform across all spatial frequencies; it is related to the level of detail in the image (i.e., spatial frequency). This means that the lens primarily provides a soft and significant contrast reduction within a certain spatial frequency range to generate a myopia control signal; in this embodiment, the contrast reduction range is approximately 20% to 40%.

[0232] In step S32, the test mainly includes morphology verification: specifically, a white light interferometer or an atomic force microscope can be used to measure the surface of the lens, calculate the measured surface power spectral density (PSD), and compare it with the target surface power spectral density (PSD) as the core acceptance indicator.

[0233] The test may also include optical verification, including: measuring whether the angle-resolved scattering distribution of the lens conforms to a Lambertian distribution; integrating the measured angle-resolved scattering distribution to obtain the total scattering integral, and verifying whether the obtained total scattering integral conforms to the target total scattering integral. Specifically, an angle-resolved scattering measurement system equipped with a rotating detector can be used to measure the angle-resolved scattering distribution in the 400-700 nm band. Gaussian fitting is performed on the ARS data to extract the scattering angle distribution width and peak angle, and the integrated scattering intensity within the target angle range is calculated. This is then combined with haze testing and transmission spectroscopy measurements for a comprehensive evaluation.

[0234] The measured angle-resolved scattering distribution satisfies the following condition:

[0235] (i) When the wavelength λ = 550 nm and the incident angle θ = 0°, the angle φ of the main scattering peak peak Satisfying 5°≤φ peak ≤12°;

[0236] (ii) The ARS value in the 10° direction is 0.15–0.40 sr -1 (Based on incident light intensity); ARS value at 30° ≤ 0.001 sr -1 ;

[0237] (iii) Transmittance at 0° ≥ 85%. As described above, the density of the light diffusion center array in the point diffusion anti-myopia lens is 5-10 units / mm², and the surface roughness RMS satisfies 0.5μm≤h≤3μm.

[0238] Example 2:

[0239] refer to Figure 3 Based on the above path planning method, the present invention also provides a lens, which is manufactured using the lens customization design method of the aforementioned embodiment 1, and the angular resolution scattering distribution of the lens conforms to the ideal Lambertian scattering characteristics.

[0240] The parameters and design requirements for the lenses are shown in Table 1 below:

[0241]

[0242] The specific implementation method of this embodiment is the same as that of Embodiment 1, and will not be repeated here. Please refer to the description of Embodiment 1 for details.

[0243] The lens and lens customization design method described in the above embodiments achieve precise quantification and design optimization of scattering performance by processing the lens based on the target angle-resolved scattering distribution and target surface power spectral density. Based on the target optical performance parameters, the target optical structure parameters of the lens are determined, realizing a quantitative correlation between the lens's microstructure parameters and optical performance, thus improving design reliability. The processed lens effectively homogenizes the retinal illuminance distribution, reduces local light intensity peaks, thereby reducing image signal contrast, maintaining high transmittance while achieving specific light scattering control, significantly improving visual comfort, alleviating eye fatigue symptoms, and allowing adjustment of scattering characteristic parameters to meet different user needs. In the technical solution of this invention, a specific target angle-resolved scattering distribution (ARS) is designed for the eye habits and myopia development trend of adolescents. The target gently and uniformly reduces the light intensity entering the eye at all angles throughout the entire field of view. This is equivalent to adding a slight, uniform "background noise" to the visual signal, thereby reducing the overall image contrast.

[0244] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention and form different embodiments.

[0245] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for custom lens design, characterized in that: The target light intensity attenuation rate of the lens is determined based on eye parameters; the target total scattering integral of the lens is determined based on the target light intensity attenuation rate; the target total scattering integral of the lens is the ratio of the light power scattered by the lens to the total incident light power; Determining the target angular-resolved scattering distribution of the lens based on the total target scattering integral includes ensuring that the target angular-resolved scattering distribution of the lens conforms to ideal Lambertian scattering characteristics based on the total target scattering integral; wherein the target angular-resolved scattering distribution of the lens is: ARS target (i s ) = (TIS target / p) cos(θ s ); The ARS target The TIS is a target angle-resolved scattering distribution for the lens. target θ is the total target scattering integral of the lens. s The scattering angle represents the angle between the scattering direction and the normal to the mirror surface of the lens. Determining the target surface power spectral density of the lens based on the target angle-resolved scattering distribution includes: establishing the correlation between the target angle-resolved scattering distribution and the target surface power spectral density, expressed as: ; The scattering angular domain is mapped to the surface spatial frequency domain based on the grating equation, which is: ; The target surface power spectral density of the lens is obtained as follows: ; Where λ is the wavelength of the incident light, and θ s Let θ be the scattering angle. i Where is the incident angle, Q is the optical factor, f is the surface spatial frequency, and K is the normalization constant; The target optical structure parameters of the lens are determined based on the target angularly resolved scattering distribution and the target surface power spectral density; the target optical structure parameters of the lens include at least the target root-mean-square roughness of the lens, which is obtained by integrating the target surface power spectral density over the effective bandwidth. ； in, and These represent the minimum and maximum values ​​of the effective bandwidth; Based on the target optical structure parameters, target angle-resolved scattering distribution, and target surface power spectral density, processing parameters are set, and the lens is processed so that the measured surface power spectral density of the lens is within the set target surface power spectral density range, and the measured angle-resolved scattering distribution of the lens conforms to an ideal Lambertian distribution; the ideal Lambertian scattering characteristics include: the lens surface has completely random and isotropic surface roughness and randomly arranged microstructures; the randomly arranged microstructures include: extremely low-frequency control microstructures determined by the overall macroscopic position of micro-points; low-to-mid-frequency control structures determined by the random positions of micro-points; and mid-to-high-frequency control structures determined by the random depth and / or shape of micro-points.

2. The lens customization design method according to claim 1, characterized in that, The process of setting processing parameters based on the target optical structure parameters, the target angular-resolved scattering distribution, and the target surface power spectral density, and processing the lens to ensure that the measured surface power spectral density of the lens is within the set target surface power spectral density range, includes: The processing parameters are set based on the target root mean square roughness of the lens, and the lens is processed. The processed lens was tested to measure the actual surface power spectral density of the processed lens; If the measured surface power spectral density is outside the set target surface power spectral density range, adjust the processing parameters and / or the target surface power spectral density, repeat the processing and testing; If the measured surface power spectral density is within the set target surface power spectral density range, the lens processing is complete.

3. The lens customization design method according to claim 2, characterized in that, The test also includes optical verification, including: Measure whether the angle-resolved scattering distribution of the lens conforms to a Lambertian distribution; The total scattering integral is obtained by integrating the measured angle-resolved scattering distribution, and the obtained total scattering integral is verified to conform to the target total scattering integral.

4. A lens, characterized in that, The lens is manufactured using the custom lens design method described in any one of claims 1-3, and the angular resolution scattering distribution of the lens conforms to the ideal Lambertian scattering characteristics.

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