A method for designing a personalized ophthalmic lens and an ophthalmic lens

Abstract

The application belongs to the technical field of eye optics, and relates to a design method of personalized spectacle lenses and the spectacle lenses. The design method comprises the following steps: constructing a mirror-eye joint mathematical model based on a frame posture and eyeball rotation, and obtaining a theoretical dioptric power calculation formula of a lens surface under a prescribed dioptric power through analytical calculation on the mathematical model; constructing a mirror-eye system containing a to-be-optimized lens and different rotation angle eye models based on a basic eye model, the prescribed dioptric power, the frame posture, the central dioptric power, the refractive index and the central thickness of the inner and outer surfaces of the lens; calculating the actual dioptric power of the to-be-optimized lens surface based on the intersection of the visual axis of the human eye of the different rotation angle eye models and the surface of the to-be-optimized lens; taking the minimum absolute value of the difference between the actual dioptric power and the theoretical dioptric power of the surface of the to-be-optimized lens as the target, and simultaneously ensuring the imaging quality and the processability of the lens, optimizing the inner surface parameters of the to-be-optimized lens, and obtaining the personalized spectacle lenses considering the frame posture and the eyeball rotation.

Description

Technical Field

[0001] This invention relates to the field of optometry technology, and in particular to a method for designing personalized eyeglass lenses and the eyeglass lenses themselves. Background Technology

[0002] Refractive errors, such as myopia and astigmatism, have become common health problems faced by teenagers. Among the common methods of correcting refractive errors, eyeglasses have the advantages of being convenient, economical, reversible, and without side effects, and are currently the most widely used correction method.

[0003] The purpose of eyeglasses is to adjust the convergence and divergence of incident light so that the image focal point falls on the retina. While traditional spherical lenses have accurate refractive power in the central area and can effectively correct refractive defects in the human eye, they have significant aberrations in the peripheral area and are relatively thick at the edges, affecting wearing comfort and aesthetics. Aspherical lenses, by optimizing the curvature distribution of the lens surface, significantly reduce aberrations and improve image clarity, while also achieving thinner and lighter lenses. Therefore, aspherical lenses are widely used in the design of eyeglasses in current technology. However, existing technologies use a fixed refractive power distribution pattern when designing aspherical lenses, ignoring the correlation between the lens and the wearer's dynamic vision and frame posture. That is, they ignore the influence of parameters such as the wearer's eye rotation, lens-to-eye distance, frame tilt angle, and face curvature angle on the actual effective refractive power, optical aberration distribution, and field of view adaptability of the lens. This results in a feeling of good during static testing (trial wear) under ideal conditions, but an inability to adapt to the wearer's eye movements and frame posture during dynamic use in real working conditions (i.e., actual wear), leading to discomfort and affecting the wearer's visual comfort.

[0004] In summary, existing methods for designing aspherical lenses have the problem that the lenses cannot adapt to the wearer's eye movements and frame posture during actual wear, thus affecting the wearer's visual comfort. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem that aspherical lenses designed by existing methods cannot adapt to the wearer's eye movements and frame posture during actual wear, thus affecting the wearer's visual comfort.

[0006] To address the aforementioned technical problems, this invention provides a method for designing personalized eyeglass lenses, comprising:

[0007] A joint mathematical model of lens and eye based on frame posture and eye rotation was constructed. The mathematical model was analyzed and calculated to obtain the theoretical refractive power calculation formula of the lens surface under the prescription refractive power.

[0008] Based on the basic eye model, prescription refractive power, frame posture, central refractive power, refractive index and central thickness of the inner and outer surfaces of the lens, multiple lens-eye systems are constructed, consisting of the lens to be optimized and eye models with different rotation angles.

[0009] Based on the theoretical refractive power calculation formula and multiple lens systems, the actual refractive power at the intersection of the human eye visual axis and the surface of the lens to be optimized is calculated for eye models with different rotation angles, thus obtaining the actual refractive power of the surface of the lens to be optimized.

[0010] The optimization objective is to minimize the absolute value of the difference between the actual refractive power and the theoretical refractive power of the lens surface to be optimized. The inner surface parameters of the lens to be optimized are then optimized to obtain personalized eyeglass lenses.

[0011] Preferably, a joint mathematical model of lens and eye based on frame posture and eye rotation is constructed, and analytical calculations are performed on the mathematical model to obtain the theoretical refractive power calculation formula of the lens surface under the prescription refractive power, including:

[0012] Establish a human eye coordinate system with the center of rotation of the human eye as the origin, and establish a lens coordinate system with the geometric center of the lens surface as the origin based on the frame tilt angle and the face curvature angle;

[0013] Based on the intersection of the human eye's visual axis and the lens plane, and the distance from the center of rotation of the human eye to the geometric center of the lens surface, construct the direction vector of the line containing the human eye's visual axis;

[0014] Based on the direction vector of the line containing the human eye's visual axis and the coordinates of a point on the line containing the human eye's visual axis, construct the parametric equation of the line containing the human eye's visual axis.

[0015] Based on the coordinates and normal vector of a point on the lens surface, construct the surface equation of the lens;

[0016] Solve the parametric equations of the line containing the human eye's visual axis and the equations of the lens surface simultaneously to obtain the intersection points of the human eye's visual axis and the lens surface at different viewing angles, and calculate the distance between each intersection point and the center of rotation of the human eye.

[0017] Based on the distance between each intersection point and the center of rotation of the human eye, the distance between each intersection point and the anterior surface of the human cornea is calculated. Thus, according to the equivalent refractive power calculation formula, the theoretical refractive power calculation formula of the lens surface under the prescription refractive power is obtained.

[0018] Preferably, the direction vector of the line containing the human eye's visual axis Represented as:

[0019] ,

[0020] ,

[0021] ,

[0022] in, This represents the direction vector along the x-axis of the line where the human eye is located; This represents the direction vector along the y-axis of the line where the human eye is located; This represents the direction vector along the z-axis of the line where the human eye is located; The x-coordinate of the intersection point of the human eye's visual axis and the lens surface; The vertical coordinate of the intersection point of the human eye's visual axis and the lens surface; It represents the distance from the center of rotation of the human eye to the geometric center of the lens surface; Indicates the angle of vertical movement of the eyeball. Indicates the angle of left and right eye movement;

[0023] The parametric equation of the line containing the human eye's visual axis is expressed as:

[0024] ,

[0025] in, Represents the three-dimensional spatial coordinates of any point on the straight line containing the human eye's visual axis; Represents the three-dimensional spatial coordinates of a point on the line containing the human eye's visual axis; Indicates the fitted parameters;

[0026] The surface equation of the lens is expressed as:

[0027] ,

[0028] in, Represents the three-dimensional spatial coordinates of any point on the lens surface; Represents the three-dimensional spatial coordinates of a point on the surface of the lens; express The normal vector;

[0029] ,

[0030] The formula for calculating the distance between each intersection point and the center of rotation of the human eye is:

[0031] ,

[0032] in, This represents the distance between the intersection of the human eye's visual axis and the lens plane and the center of rotation of the human eye from the i-th viewpoint, i.e., the distance between the i-th intersection point and the center of rotation of the human eye. Represents the three-dimensional spatial coordinates of the i-th intersection point;

[0033] The formula for calculating the distance between each intersection point and the anterior surface of the human cornea is as follows:

[0034] ,

[0035] in, This represents the distance between the i-th intersection point and the anterior surface of the human cornea; It represents the distance between the center of rotation of the human eye and the anterior surface of the cornea;

[0036] The theoretical refractive power of a lens surface under the prescribed refractive power is calculated using the following formula:

[0037] ,

[0038] in, Indicates the prescription refractive power of the lens surface; Indicates the lens surface at the prescribed refractive power Theoretical refractive power below; It represents a matrix composed of the distances from each grid point on the lens surface to the anterior surface of the cornea when they intersect with the visual axis of the human eye;

[0039] ,

[0040] in, The prescription refractive power of the grid point in the m-th row and n-th column on the lens surface;

[0041] ,

[0042] in, This indicates the grid point in the m-th row and n-th column of the lens surface at the prescribed refractive power. The theoretical refractive power is as follows.

[0043] Preferably, based on the theoretical refractive power calculation formula and multiple lens systems, the actual refractive power at the intersection of the human eye's visual axis and the surface of the lens to be optimized is calculated for eye models with different rotation angles, including:

[0044] Based on the frequency of use at different rotation angles, optimization weights are assigned to each eye system.

[0045] Based on each lens system and its optimization weight, the actual refractive power at the intersection of the human eye visual axis and the surface of the lens to be optimized is obtained for each rotation angle eye model, thus obtaining the actual refractive power of the surface of the lens to be optimized.

[0046] Preferably, when the rotation angle is 0° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 10.

[0047] When the rotation angle is -20° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 8.

[0048] When the rotation angle is 10° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 1.

[0049] When the rotation angle is 0° in the vertical direction and 20° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 3.

[0050] When the rotation angle is 0° in the vertical direction and -20° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 3.

[0051] When the rotation angle is -15° in the vertical direction and 15° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 5.

[0052] When the rotation angle is -15° in the vertical direction and -15° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 5.

[0053] In the vertical direction, a positive value indicates upward rotation, and a negative value indicates downward rotation; in the horizontal direction, a positive value indicates leftward rotation, and a negative value indicates rightward rotation.

[0054] Preferably, the actual refractive power of the lens surface to be optimized Represented as:

[0055] ,

[0056] in, This represents the refractive power of the grid point in the m-th row and n-th column of the lens surface to be optimized.

[0057] Preferably, the optimization objective Represented as:

[0058] ,

[0059] in, This indicates the actual refractive power of the lens surface to be optimized; This indicates the theoretical refractive power of the lens surface to be optimized at the prescribed refractive power.

[0060] Preferably, optimizing the inner surface parameters of the lens to be optimized includes:

[0061] Step 1: Using a sampling step size of 0.1 mm, read the radius of curvature of the inner and outer surfaces of the lens to be optimized, calculate the refractive power value of each grid point on the inner surface of the lens to be optimized, thereby calculating the actual refractive power of the inner surface of the lens to be optimized, and calculating the absolute value of the difference between the actual refractive power and the theoretical refractive power.

[0062] Step 2: Adjust the polynomial coefficients of the inner surface of the lens to be optimized, and return to Step 1 until the absolute value of the difference between the actual refractive power and the theoretical refractive power is minimized.

[0063] Preferably, after adjusting the polynomial coefficients of the inner surface of the lens to be optimized, the process further includes:

[0064] The first or second derivative of the inner surface of the lens to be optimized is adjusted using the SDRV operand so that the changes in the sag of both the edge aperture and the non-edge aperture on the inner surface of the lens to be optimized are either positive or negative.

[0065] The inclination angle of each grid point on the inner surface of the lens to be optimized is obtained by solving the arctangent of the slope data of each grid point on the inner surface of the lens to be optimized.

[0066] Control the tilt angle of each grid point to avoid reverse tilting of the inner surface of the lens to be optimized.

[0067] The present invention also provides an eyeglass lens, which is designed by the above-described personalized eyeglass lens design method.

[0068] The personalized eyeglass lens design method provided in this application has the following beneficial effects:

[0069] 1. By constructing a joint mathematical model of eye and lens, considering eye rotation and frame posture (frame tilt, lens-eye distance, and face curvature), the theoretical refractive power at the intersection point of the human eye's visual axis and the lens can be accurately calculated based on the prescription refractive power, thus obtaining the theoretical refractive power of the lens surface when the eye rotates. By constructing eye models with different rotation angles, the actual refractive power at the intersection point of the human eye's visual axis and the lens at different times of eye rotation can be obtained when optimizing the lens, thus obtaining the actual refractive power of the lens surface when the eye rotates. Then, with the goal of minimizing the absolute value of the difference between the actual refractive power and the theoretical refractive power of the lens surface to be optimized, the inner surface parameters of the lens to be optimized are optimized. This can dynamically compensate for the additional refractive deviations introduced by dynamic use such as eye rotation and frame posture, so that the refractive power felt by the human eye when actually wearing the lens remains stable, effectively alleviating visual fatigue and discomfort caused by the mismatch between lens design and actual visual state.

[0070] 2. By constructing a human eye coordinate system with the center of human eye rotation as the origin, and a lens coordinate system based on the frame tilt angle and face curvature angle with the geometric center of the lens surface as the origin, a lens-eye joint model considering eye rotation and frame posture (frame tilt angle, lens-eye distance, and face curvature angle) can be obtained. Through spatial coordinate transformation and analytical calculation of the two coordinate systems, the theoretical refractive power of the intersection point when the lens intersects with the eye at different viewing angles (different human eye visual axes) can be accurately calculated, thereby obtaining the theoretical refractive power of each point on the lens surface when the eye rotates.

[0071] 3. Using Zemax software, eye models with different rotation angles and lenses to be optimized are constructed to form an eye system. ZPL / ZPLM scripts are used to directly read and optimize the lens refractive power. Different optimization weights are assigned to the eye system with different viewing angles (different visual axes) based on the frequency of use of different rotation angles of the human eye. This results in a general improvement in the MTF value of the optimized lens in commonly used optical areas (such as within 20mm diameter), especially in key viewing structures. The optical quality of the lens center and peripheral field of view is improved, which can meet the image quality requirements of the human eye in dynamic vision. Attached Figure Description

[0072] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0073] Figure 1 Flowchart of the personalized eyeglass lens design method provided for this application;

[0074] Figure 2 A schematic diagram of a combined lens and eye model provided in this application;

[0075] Figure 3 A schematic diagram of another lens-eye combined model provided in this application;

[0076] Figure 4 The ZPL programming flowchart provided for this application;

[0077] Figure 5 A schematic diagram of a mirror system constructed in Zemax for this application;

[0078] Figure 6 A schematic diagram of the refractive power distribution on the lens surface obtained by prior art design for this application;

[0079] Figure 7 A schematic diagram of the refractive power distribution on the surface of a spectacle lens designed using the method provided in this application;

[0080] Figure 8 A comparative schematic diagram of the MTF curves of spectacle lenses in the prior art and spectacle lenses designed using the method provided in this application under structures 1 to 4; wherein, Figure 8 (a) in the figure shows the MTF curve of the spectacle lens in structure 1 in the prior art. Figure 8 (b) shows the MTF curve of the spectacle lens designed in this application under structure 1. Figure 8 (c) in the figure represents the MTF curve of the spectacle lens in structure 2 in the prior art. Figure 8(d) in the figure represents the MTF curve of the spectacle lens designed in this application under structure 2. Figure 8 (e) in the figure represents the MTF curve of the spectacle lens in structure 3 in the prior art. Figure 8 In the figure, (f) represents the MTF curve of the spectacle lens designed in this application under structure 3. Figure 8 In the figure, (g) represents the MTF curve of the spectacle lens in structure 4 in the prior art. Figure 8 (h) in the figure represents the MTF curve of the spectacle lens designed in this application under structure 4;

[0081] Figure 9 A comparative schematic diagram of the MTF curves of existing spectacle lenses and spectacle lenses designed using the method provided in this application under structures 5 to 7; wherein... Figure 9 (a) in the figure shows the MTF curve of the spectacle lens in structure 5 in the prior art. Figure 9 (b) shows the MTF curve of the spectacle lens designed in this application under structure 5. Figure 9 (c) in the figure represents the MTF curve of the spectacle lens in the prior art under structure 6. Figure 9 (d) in the figure represents the MTF curve of the spectacle lens designed in this application under structure 6. Figure 9 (e) in the figure represents the MTF curve of the spectacle lens in structure 7 in the prior art. Figure 9 (f) in the figure represents the MTF curve of the spectacle lens designed in this application under structure 7. Detailed Implementation

[0082] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0083] Please see Figure 1 , Figure 1 The diagram shown is a flowchart of the personalized eyeglass lens design method provided in this application, which specifically includes steps S10 to S40:

[0084] S10: Construct a joint mathematical model of lens and eye based on frame posture and eye rotation, perform analytical calculations on the mathematical model, and obtain the theoretical refractive power calculation formula of the lens surface under the prescription refractive power.

[0085] Specifically, the posture of the eyeglasses includes the frame tilt angle, lens-to-eye distance, and face curvature.

[0086] S20: Based on the basic eye model, prescription refractive power, frame posture, central refractive power, refractive index and central thickness of the inner and outer surfaces of the lens, construct multiple lens-eye systems consisting of the lens to be optimized and eye models with different rotation angles.

[0087] S30: Based on the theoretical refractive power calculation formula and multiple lens systems, calculate the actual refractive power at the intersection of the human eye visual axis and the surface of the lens to be optimized for different rotation angle eye models, and obtain the actual refractive power of the surface of the lens to be optimized.

[0088] S40: The optimization objective is to minimize the absolute value of the difference between the actual refractive power and the theoretical refractive power of the lens surface to be optimized, thereby optimizing the inner surface parameters of the lens to be optimized and obtaining personalized eyeglasses.

[0089] Furthermore, step S10 specifically includes S100~S105:

[0090] S100: Establish a human eye coordinate system with the center of rotation of the human eye as the origin, and establish a lens coordinate system with the geometric center of the lens surface as the origin based on the frame tilt angle and the face curvature angle.

[0091] For example, such as Figure 2 The diagram shown is a schematic of a combined lens-eye model provided in this application, specifically including a human eye coordinate system with the center of human eye rotation as the origin. A lens coordinate system with the geometric center of the lens as the origin. ,in, Indicates the angle of vertical movement of the eyeball. Indicates the angle of left and right eye movement. It represents the distance from the center of rotation of the human eye to the geometric center of the lens surface; Figure 3 The image shown is in Figure 2 Introducing frame tilt on the basis Kneading corners After (the lens coordinate system becomes) Another schematic diagram of the lens-eye combined model.

[0092] It can be seen that, considering the frame tilt angle Kneading corners The positional relationship between the human eye coordinate system and the lens coordinate system differs significantly between the combined lens-eye model and the combined lens-eye model that does not consider these two parameters.

[0093] S101: Based on the intersection of the human eye's visual axis and the lens surface, and the distance from the center of rotation of the human eye to the geometric center of the lens surface, construct the direction vector of the line containing the human eye's visual axis.

[0094] Specifically, when a human eye observes an object through a lens, the visual axis of the eye will inevitably intersect with the surface of the lens, creating an intersection point. The coordinates of this intersection point are... Then by Figure 3 The triangular relationship in the equation can be obtained as follows:

[0095] ,

[0096] ,

[0097] Furthermore, the angle of eye rotation can represent the direction vector of the line containing the human eye's visual axis:

[0098] ,

[0099] in, This represents the direction vector along the x-axis of the line where the human eye is located; This represents the direction vector along the y-axis of the line where the human eye is located; This represents the direction vector along the z-axis of the line where the human eye is located.

[0100] S102: Based on the direction vector of the line containing the human eye's visual axis and the coordinates of a point on the line containing the human eye's visual axis, construct the parametric equation of the line containing the human eye's visual axis.

[0101] Specifically, when the line containing the human eye's visual axis passes through the point... At that time, the parametric equation of the line containing the human eye's visual axis is expressed as:

[0102] ,

[0103] in, It represents the three-dimensional spatial coordinates of any point on the straight line containing the human eye's visual axis.

[0104] S103: Construct the surface equation of the lens based on the coordinates and normal vector of a point on the lens surface.

[0105] Specifically, assuming the lens surface is beyond a certain point... Its normal vector is The surface equation of the lens is then expressed as:

[0106] ,

[0107] in, This represents the three-dimensional spatial coordinates of any point on the surface of the lens.

[0108] S104: Solve the parametric equations of the line containing the human eye's visual axis and the equations of the lens surface simultaneously to obtain the intersection points of the human eye's visual axis and the lens surface under different viewing angles, and calculate the distance between each intersection point and the center of rotation of the human eye.

[0109] Solving the parametric equations of the line containing the human eye's visual axis and the equations of the lens surface simultaneously yields the following results: ,Will By substituting the parametric equation of the line containing the human eye's visual axis, the coordinates of the intersection points between the human eye's visual axis and the lens surface at different viewing angles can be obtained:

[0110] Based on the principle of spatial coordinate transformation, the human eye coordinate system and lens coordinate system The relationship between them is:

[0111] ,

[0112] Wherein, rotation matrix Translation matrix ;

[0113] Introducing frame tilt angle Kneading corners Afterwards, as Figure 3 As shown, the human eye coordinate system and lens coordinate system The relationship between them is:

[0114] ,

[0115] Wherein, the rotation matrix becomes The translation matrix becomes ;

[0116] Furthermore, based on the introduced frame tilt angle Kneading corners The coordinate system can be calculated by considering the spatial transformation relationship between the latter two coordinate systems. Below are the coordinates of the intersection points of the human eye's visual axis and the lens surface from different viewpoints. Specifically, the formula for calculating the distance from each intersection point of the human eye's visual axis and the lens surface to the center of rotation of the human eye from different viewpoints is as follows:

[0117] ,

[0118] in, This represents the distance between the intersection of the human eye's visual axis and the lens surface and the center of rotation of the human eye from the i-th viewpoint, i.e., the distance between the i-th intersection point and the center of rotation of the human eye. Represents the three-dimensional spatial coordinates of the i-th intersection point.

[0119] S105: Based on the distance between each intersection point and the center of rotation of the human eye, calculate the distance between each intersection point and the anterior surface of the human cornea, and then obtain the theoretical refractive power calculation formula of the lens under the prescription refractive power according to the equivalent refractive power calculation formula.

[0120] Specifically, the formula for calculating the distance between each intersection point and the anterior surface of the human cornea is as follows:

[0121] ,

[0122] in, This represents the distance between the i-th intersection point and the anterior surface of the human cornea; It represents the distance between the center of rotation of the human eye and the anterior surface of the cornea;

[0123] The theoretical refractive power of a lens surface under the prescribed refractive power is calculated using the following formula:

[0124] ,

[0125] in, Indicates the prescription refractive power of the lens surface; Indicates the lens surface at the prescribed refractive power Theoretical refractive power below; It represents a matrix composed of the distances from each grid point on the lens surface to the anterior surface of the cornea when they intersect with the visual axis of the human eye;

[0126] ,

[0127] in, The prescription refractive power of the grid point in the m-th row and n-th column on the lens surface;

[0128] ,

[0129] in, This indicates the grid point in the m-th row and n-th column of the lens surface at the prescribed refractive power. The theoretical refractive power is as follows.

[0130] Furthermore, step S30 specifically includes S300~S301:

[0131] S300: Based on the frequency of use at different rotation angles, optimize weights are assigned to each eye system.

[0132] S301: Based on each lens system and its optimization weight, obtain the actual refractive power at the intersection of the human eye visual axis and the surface of the lens to be optimized for each rotation angle eye model, and obtain the actual refractive power of the surface of the lens to be optimized.

[0133] The optimization weights assigned to each lens system are determined based on the frequency of use and visual importance of the visual field points at the rotation angle of the eye model in each system. Among the optimization weights, the refractive power optimization at the intersection of the human eye's visual axis and the surface of the lens to be optimized at each rotation angle is given the largest weight.

[0134] Therefore, in a preferred embodiment of this application, when the rotation angle is 0° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 10.

[0135] When the rotation angle is -20° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 8.

[0136] When the rotation angle is 10° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 1.

[0137] When the rotation angle is 0° in the vertical direction and 20° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 3.

[0138] When the rotation angle is 0° in the vertical direction and -20° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 3.

[0139] When the rotation angle is -15° in the vertical direction and 15° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 5.

[0140] When the rotation angle is -15° in the vertical direction and -15° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 5.

[0141] In the vertical direction, a positive value indicates upward rotation, and a negative value indicates downward rotation; in the horizontal direction, a positive value indicates leftward rotation, and a negative value indicates rightward rotation.

[0142] The specific weight allocation data is shown in Table 1:

[0143] Table 1

[0144]

[0145] It should be noted that the above weight allocation data is only a specific example provided in this application, and the actual allocation data can be fine-tuned according to actual needs.

[0146] Specifically, the actual refractive power of the lens surface to be optimized. Represented as:

[0147] ,

[0148] in, This represents the refractive power of the grid point in the m-th row and n-th column of the lens surface to be optimized.

[0149] Further optimize the objectives Represented as:

[0150] ,

[0151] in, This indicates the actual refractive power of the lens surface to be optimized; This indicates the theoretical refractive power of the lens surface to be optimized at the prescribed refractive power.

[0152] Based on the above derivation process, it can be seen that considering the eye movement factors of the frame posture will generate additional refractive power, which needs to be compensated for when designing lenses. Therefore, this application takes minimizing the absolute value of the difference between the actual refractive power and the theoretical refractive power calculated when considering the frame posture and eye movement factors as the main optimization objective.

[0153] Furthermore, such as Figure 4 As shown, this embodiment of the application utilizes a default wavefront function and ZPL / ZPLM operation functions to optimize the inner surface parameters of the lens to be optimized. Specifically, optimizing the inner surface parameters of the lens to be optimized using ZPL / ZPLM operation functions includes steps 1 to 2:

[0154] Step 1: Using a sampling step size of 0.1 mm, read the radius of curvature of the inner and outer surfaces of the lens to be optimized, calculate the refractive power value of each grid point on the inner surface of the lens to be optimized, thereby calculating the actual refractive power of the lens to be optimized, and calculating the absolute value of the difference between the actual refractive power and the theoretical refractive power.

[0155] Step 2: Adjust the polynomial coefficients of the inner surface of the lens to be optimized, and return to Step 1 until the absolute value of the difference between the actual refractive power and the theoretical refractive power is minimized.

[0156] Specifically, this application only optimizes the inner surface of the lens. To obtain a high degree of freedom, the surface shape of the inner surface of the lens is an extended polynomial, and its surface shape sag is... Represented as:

[0157] ,

[0158] in, Indicates curvature; Indicates radial distance; Represents the conic constant; Denotes the coefficients of the i-th polynomial; Denotes the basis function term of the i-th polynomial; The term indicates the number of terms; the polynomial is simply a power series in the x and y directions. The first term is x, then y, followed by x*x, x*y, y*y, and so on. There are 2 terms for the first degree, 3 terms for the second degree, 4 terms for the third degree, and so on. The highest degree is 20, which makes the maximum total number of aspherical coefficients of the polynomial 230. The data values ​​at positions such as x and y are divided by a normalized radius to obtain a dimensionless polynomial coefficient.

[0159] It should be noted that in reality, the range of eye movement is limited, and the head will turn when discomfort is felt. Therefore, the optimization area for the inner surface can be concentrated within a 20mm diameter range.

[0160] Furthermore, after adjusting the polynomial coefficients of the inner surface of the lens to be optimized, steps 2-1 to 2-3 are also included:

[0161] Step 2-1: Use the SDRV operand to adjust the first or second derivative of the inner surface of the lens to be optimized, so that the change in the sag of both the edge aperture and the non-edge aperture of the inner surface of the lens to be optimized is either positive or negative.

[0162] Step 2-2: Solve the arctangent of the slope data of each grid point on the inner surface of the lens to be optimized to obtain the tilt angle of each grid point on the inner surface of the lens to be optimized.

[0163] Steps 2-3: Control the tilt angle of each grid point to avoid the inner surface of the lens to be optimized tilting in the opposite direction.

[0164] Specifically, this application avoids the lens from curvature by constraining the first-order or second-order data of the sagitta of the inner surface of the lens to be optimized, thereby satisfying the machinability of the lens.

[0165] This application also provides an eyeglass lens, which is designed by the above-described personalized eyeglass lens design method.

[0166] This application also provides a specific example to further explain the above-described method for designing personalized eyeglass lenses.

[0167] In this embodiment, the refractive power (i.e., prescription refractive power) of the person's left eye is -3.25D, and the distance from the center of rotation of the person's eye to the geometric center of the inner surface of the lens is... d It is 27mm (if the outer surface is calculated, then...). d (The center thickness of the lenses also needs to be added), the interpupillary distance is 13mm, and the frame tilt angle is... The face bend angle is 10°. It is 5°.

[0168] The refractive index of the lens to be optimized is 1.597, the center thickness is 1.3mm, and the lens has two refractive surfaces: the outer surface is spherical with a diopter of 2.155D and a corresponding radius of curvature of 277.03mm, and the inner surface is aspherical with a central diopter of -5.405D and a corresponding radius of curvature of 110.45mm.

[0169] like Figure 5 The diagram shown is a schematic of a lens system constructed in Zemax according to this application, wherein the pupil size is 3.4 mm and the wavelength is 555 nm.

[0170] The optimization weight data for each lens system are shown in Table 1.

[0171] Table 2 shows the relevant parameters of the inner surface of the lens to be optimized and the relevant parameters of the inner surface of the lens after ZEMAX optimization in this embodiment:

[0172] Table 2

[0173]

[0174] This application also compares the refractive power distribution of the spectacle lens designed in this embodiment with that of a monofocal aspherical lens of the same specification in the prior art, such as... Figure 6 The diagram shown is a schematic representation of the refractive power distribution on the lens surface obtained by the prior art design provided in this application. Figure 7 The diagram shown is a schematic of the refractive power distribution on the surface of the spectacle lens designed in this embodiment. It can be seen that the refractive power distribution of the spectacle lens designed in this embodiment is consistent with the theoretically calculated refractive power distribution trend, which is more in line with the actual use of the human eye and improves the comfort of wearing glasses.

[0175] Furthermore, the image quality of the spectacle lens designed in this embodiment was compared with that of a single-focal aspherical lens of the same specification in the prior art, such as... Figure 8 and Figure 9 The image shown is a diagram illustrating the comparison results.

[0176] in, Figure 8 A comparative schematic diagram of the MTF curves of spectacle lenses in the prior art and spectacle lenses designed using the method provided in this application under structures 1 to 4; Figure 8 (a), (c), (e), and (g) in the figure correspond to the MTF curves of spectacle lenses in structures 1 to 4 in the prior art, respectively. Figure 8 (b), (d), (f), and (h) in the figure represent the MTF curves of the spectacle lens designed in this application under structures 1 to 4. It can be seen that, in structure 1, the MTF value (average of sagittal MTF and meridional MTF) of the spectacle lens designed in this application is improved by 96.97% compared with the spectacle lens of the prior art at 100 lp / mm, while in structure 2, it is reduced by 1.69%. In structures 3 and 4, the MTF value of the spectacle lens designed in this application is improved by 128.57% and 457.14% respectively compared with the spectacle lens of the prior art at 70 lp / mm (spurious resolution exists before 100 lp / mm).

[0177] Figure 9 A comparative schematic diagram of the MTF curves of existing spectacle lenses and spectacle lenses designed using the method provided in this application under structures 5 to 7; wherein... Figure 9 (a), (c), and (e) in the figure correspond to the MTF curves of spectacle lenses in structures 5 to 7 in the prior art, respectively. Figure 9(b), (d), and (f) in the figure correspond to the MTF curves of the spectacle lens designed in this application under structures 5 to 7, respectively. It can be seen that in structure 5, the MTF value of the spectacle lens designed in this application is improved by 17.95% compared with the spectacle lens of the prior art at 100 lp / mm; in structure 6, the MTF value of the spectacle lens designed in this application is improved by 44.62% compared with the spectacle lens of the prior art at 100 lp / mm; and in structure 7, it is reduced by 3.62%.

[0178] Although the MTF performance of the spectacle lens designed in this embodiment decreases slightly under both structures, the magnitude is small. Overall, the optical performance of the spectacle lens designed in this embodiment is superior to that of existing single-focal aspherical lenses of the same specification, indicating that the design method provided in this application can effectively improve the optical effect of the lens. It should be noted that structures 1 to 7 represent eye-lens systems containing eye models with different rotation angles.

[0179] In the above embodiments, only the refractive power of the inner surface of the lens was compensated. It should be noted that the method of this application can also be used to compensate the refractive power of both the inner and outer surfaces of the lens at the same time. In addition, the method of this application can be used to calculate the refractive power compensation requirements of the inner and outer surfaces of the lens, and then only a certain surface of the lens can be used for compensation design.

[0180] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0181] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0182] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0183] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0184] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for designing personalized eyeglass lenses, characterized in that, include: A joint mathematical model of lens and eye based on frame posture and eye rotation was constructed. The mathematical model was analyzed and calculated to obtain the theoretical refractive power calculation formula of the lens surface under the prescription refractive power. Specifically, it includes: Establish a human eye coordinate system with the center of rotation of the human eye as the origin, and establish a lens coordinate system with the geometric center of the lens surface as the origin based on the frame tilt angle and the face curvature angle; Based on the intersection of the human eye's visual axis and the lens plane, and the distance from the center of rotation of the human eye to the geometric center of the lens surface, construct the direction vector of the line containing the human eye's visual axis; Based on the direction vector of the line containing the human eye's visual axis and the coordinates of a point on the line containing the human eye's visual axis, construct the parametric equation of the line containing the human eye's visual axis. Based on the coordinates and normal vector of a point on the lens surface, construct the surface equation of the lens; Solve the parametric equations of the line containing the human eye's visual axis and the equations of the lens surface simultaneously to obtain the intersection points of the human eye's visual axis and the lens surface at different viewing angles, and calculate the distance between each intersection point and the center of rotation of the human eye. Based on the distance between each intersection point and the center of rotation of the human eye, the distance between each intersection point and the anterior surface of the human cornea is calculated. Then, according to the equivalent refractive power calculation formula, the theoretical refractive power calculation formula of the lens surface under the prescription refractive power is obtained. Based on the basic eye model, prescription refractive power, frame posture, central refractive power, refractive index and central thickness of the inner and outer surfaces of the lens, multiple lens-eye systems are constructed, consisting of the lens to be optimized and eye models with different rotation angles. Based on the theoretical refractive power calculation formula and multiple lens systems, the actual refractive power at the intersection of the human eye visual axis and the surface of the lens to be optimized is calculated for eye models with different rotation angles, thus obtaining the actual refractive power of the surface of the lens to be optimized. The optimization objective is to minimize the absolute value of the difference between the actual refractive power and the theoretical refractive power of the lens surface to be optimized. The inner surface parameters of the lens to be optimized are then optimized to obtain personalized eyeglass lenses.

2. The method for designing personalized eyeglass lenses according to claim 1, characterized in that, The direction vector of the line containing the human eye's visual axis Represented as: ， ， ， in, This represents the direction vector along the x-axis of the line where the human eye is located; This represents the direction vector along the y-axis of the line where the human eye is located; This represents the direction vector along the z-axis of the line where the human eye is located; The x-coordinate of the intersection point of the human eye's visual axis and the lens surface; The vertical coordinate of the intersection point of the human eye's visual axis and the lens surface; It represents the distance from the center of rotation of the human eye to the geometric center of the lens surface; Indicates the angle of vertical movement of the eyeball. Indicates the angle of left and right eye movement; The parametric equation of the line containing the human eye's visual axis is expressed as: ， in, Represents the three-dimensional spatial coordinates of any point on the straight line containing the human eye's visual axis; Represents the three-dimensional spatial coordinates of a point on the line containing the human eye's visual axis; Indicates the fitted parameters; The surface equation of the lens is expressed as: ， in, Represents the three-dimensional spatial coordinates of any point on the lens surface; Represents the three-dimensional spatial coordinates of a point on the surface of the lens; express The normal vector; ， The formula for calculating the distance between each intersection point and the center of rotation of the human eye is: ， in, This represents the distance between the intersection of the human eye's visual axis and the lens plane and the center of rotation of the human eye from the i-th viewpoint, i.e., the distance between the i-th intersection point and the center of rotation of the human eye. Represents the three-dimensional spatial coordinates of the i-th intersection point; The formula for calculating the distance between each intersection point and the anterior surface of the human cornea is as follows: ， in, This represents the distance between the i-th intersection point and the anterior surface of the human cornea; It represents the distance between the center of rotation of the human eye and the anterior surface of the cornea; The theoretical refractive power of a lens surface under the prescribed refractive power is calculated using the following formula: ， in, Indicates the prescription refractive power of the lens surface; Indicates the lens surface at the prescribed refractive power Theoretical refractive power below; It represents a matrix composed of the distances from each grid point on the lens surface to the anterior surface of the cornea when they intersect with the visual axis of the human eye; ， in, The prescription refractive power of the grid point in the m-th row and n-th column on the lens surface; ， in, This indicates the grid point in the m-th row and n-th column of the lens surface at the prescribed refractive power. The theoretical refractive power is as follows.

3. The method for designing personalized eyeglass lenses according to claim 1, characterized in that, Based on theoretical refractive power calculation formulas and multiple lens systems, the actual refractive power at the intersection of the human eye's visual axis and the surface of the lens to be optimized is calculated for eye models with different rotation angles, including: Based on the frequency of use at different rotation angles, optimization weights are assigned to each eye system. Based on each lens system and its optimization weight, the actual refractive power at the intersection of the human eye visual axis and the surface of the lens to be optimized is obtained for each rotation angle eye model, thus obtaining the actual refractive power of the surface of the lens to be optimized.

4. The method for designing personalized eyeglass lenses according to claim 3, characterized in that, When the rotation angle is 0° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 10. When the rotation angle is -20° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 8. When the rotation angle is 10° in the vertical direction and 0° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 1. When the rotation angle is 0° in the vertical direction and 20° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 3. When the rotation angle is 0° in the vertical direction and -20° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 3. When the rotation angle is -15° in the vertical direction and 15° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 5. When the rotation angle is -15° in the vertical direction and -15° in the horizontal direction, the optimization weight of the eye system composed of the eye model and the lens to be optimized is 5. In the vertical direction, a positive value indicates upward rotation, and a negative value indicates downward rotation; in the horizontal direction, a positive value indicates leftward rotation, and a negative value indicates rightward rotation.

5. The method for designing personalized eyeglass lenses according to claim 1, characterized in that, Actual refractive power of the lens surface to be optimized Represented as: ， in, This represents the refractive power of the grid point in the m-th row and n-th column of the lens surface to be optimized.

6. The method for designing personalized eyeglass lenses according to claim 1, characterized in that, Optimization Objective Represented as: ， in, This indicates the actual refractive power of the lens surface to be optimized; This indicates the theoretical refractive power of the lens surface to be optimized at the prescribed refractive power.

7. The method for designing personalized eyeglass lenses according to claim 1, characterized in that, Optimizing the inner surface parameters of the lens to be optimized includes: Step 1: Using a sampling step size of 0.1 mm, read the radius of curvature of the inner and outer surfaces of the lens to be optimized, calculate the refractive power value of each grid point on the inner surface of the lens to be optimized, thereby calculating the actual refractive power of the inner surface of the lens to be optimized, and calculating the absolute value of the difference between the actual refractive power and the theoretical refractive power. Step 2: Adjust the polynomial coefficients of the inner surface of the lens to be optimized, and return to Step 1 until the absolute value of the difference between the actual refractive power and the theoretical refractive power is minimized.

8. The method for designing personalized eyeglass lenses according to claim 7, characterized in that, After adjusting the polynomial coefficients of the inner surface of the lens to be optimized, the following steps are also included: The first or second derivative of the inner surface of the lens to be optimized is adjusted using the SDRV operand so that the changes in the sag of both the edge aperture and the non-edge aperture on the inner surface of the lens to be optimized are either positive or negative. The inclination angle of each grid point on the inner surface of the lens to be optimized is obtained by solving the arctangent of the slope data of each grid point on the inner surface of the lens to be optimized. Control the tilt angle of each grid point to avoid reverse tilting of the inner surface of the lens to be optimized.

9. A spectacle lens, characterized in that, The eyeglass lens is designed using the personalized eyeglass lens design method according to any one of claims 1 to 8.

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