Front flat type free ring curved surface myopia correction lens for XR (X-ray) glasses and manufacturing method of front flat type free ring curved surface myopia correction lens

Abstract

The invention discloses a front flat type free ring curved surface myopia correction lens for XR glasses and a manufacturing method, the front flat type free ring curved surface myopia correction lens comprises a lens base body, the lens base body is provided with a lens front surface and a lens rear surface, and the lens front surface is arranged to be an optical plane; the rear surface of the lens is arranged to be a free ring curved surface, the free ring curved surface is arranged to take a biconical curved surface as a substrate and superpose XY polynomial high-order terms, and the free ring curved surface is used for synchronously correcting defocus, astigmatism, field curvature and distortion in a full view field; according to the lens, the front surface optical plane is adopted to achieve accurate attachment to a display module, the rear surface is of a free ring curved surface structure, a lens-eye combined optical model and a global optimization algorithm are combined, cooperative correction of full-view-field aberration is achieved, and the peripheral view definition and wearing comfort are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of head-mounted display and optometry technology, specifically to a front-flat free-form torus refractive lens for XR glasses and its manufacturing method. Background Technology

[0002] With the rapid development of augmented reality, virtual reality, and mixed reality technologies, XR glasses, as the next generation of immersive display terminals, are gradually penetrating from professional fields to the mass consumer market. However, myopia is prevalent among the population, and many XR glasses users need to wear eyeglasses or contact lenses simultaneously to obtain clear virtual images. The pressure, optical interference, and field-of-view adaptation issues caused by wearing both seriously affect the immersive experience.

[0003] The shortcomings of existing technology: 1. Most XR glasses use external or internal replaceable lenses for refractive correction. The former fixes the traditional lens inside the XR glasses with an additional frame, which increases the interpupillary distance, field of view loss, stray light interference, and overall weight. The latter integrates the corrective lens inside the glasses, but often uses spherical or conventional aspherical designs, which can only achieve refractive compensation in the central field of view. In the specific wide field of view and fixed object distance usage scenarios of XR glasses, the off-axis field of view has serious astigmatism, field curvature and distortion, resulting in problems such as blurred peripheral images and edge artifacts.

[0004] 2. Traditional myopia correction lenses often use a curved surface design on the front surface, which has obvious drawbacks when applied to XR glasses: the curved surface reflects and interferes with ambient light and display light path, easily forming ghosting and stray light; the curved outer surface has poor compatibility with the flat display module or wafer of XR glasses, making it difficult to achieve precise optical coupling, affecting the transmission efficiency and image quality of the display light path; at the same time, the curved design has limitations in controlling edge thickness, increasing the overall weight of XR glasses and affecting wearing comfort.

[0005] 3. Existing design methods for freeform surface lenses are mostly geared towards general-purpose eyeglasses. Their optimization models are based on conventional viewing distances and ambient lighting conditions, failing to consider the unique characteristics of XR glasses, such as short object distances, fixed field of view, and fixed relative positions of the pupil and lens. When using the traditional damped least squares optimization method, the results are highly dependent on the initial value selection, easily getting trapped in local optima and making it difficult to obtain globally optimal surface parameters. While global optimization algorithms such as genetic algorithms possess global search capabilities, they are computationally expensive, requiring hundreds of seconds to optimize a single lens, making it difficult to meet the industrial demands of rapid iteration and personalized customization for XR glasses.

[0006] 4. Existing corrective lens design verification is mostly limited to optical simulation, lacking human factor testing verification for XR application scenarios. Many designs produce excellent image quality in simulation environments, but in actual wear, due to insufficient consideration of the visual characteristics and dynamic adaptation mechanisms of the human eye in XR usage scenarios, prolonged wear can easily lead to problems such as visual fatigue, dry eyes, and increased dizziness, failing to meet the comfort needs of XR glasses users for a long-term immersive experience. Summary of the Invention

[0007] The purpose of this invention is to provide a front-flat free-form toroidal surface myopia correction lens for XR glasses and a method for manufacturing it, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a front-panel free-torus surface myopia correction lens for XR glasses, comprising a lens substrate, wherein the lens substrate is provided with a front surface and a rear surface, the front surface of the lens being configured as an optical plane; the rear surface of the lens being configured as a free-torus surface, wherein the free-torus surface is configured with a biconical surface as a base and superimposed with higher-order terms of an XY polynomial, for simultaneously correcting defocus, astigmatism, field curvature and distortion across the entire field.

[0009] Preferably, the surface shape expression formula of the free torus is: in, , These are the central curvatures in the X and Y directions, respectively. , These represent the conic coefficients in the X and Y directions, respectively. , Let these be the coefficients of the higher-order terms of the XY polynomial. i Let N be the order of the higher-order term, and N be the highest order of the higher-order term, where N≥1.

[0010] Preferably, the lens substrate further includes a central correction zone and a peripheral optimization zone surrounding the central correction zone. The central correction zone is used to accurately correct the wearer's myopia and astigmatism, and the peripheral optimization zone is used to correct the optical aberrations of the off-axis field of view when the eyeball rotates.

[0011] This invention also provides a method for manufacturing a front-flat free-form torus refractive lens for XR glasses, the method specifically comprising: S1. Construct a combined lens-eye optical model, which includes the cornea, aqueous humor, pupil, lens, vitreous body, retina, center of rotation of the eyeball, anterior surface of the lens, and posterior surface of the lens; S2. Define the basic structure and parameters of the lens: Set the front surface of the lens as the optical plane, and determine the basic optical parameters of the lens. The basic optical parameters include the spherical power, cylindrical power, axis to be corrected, the refractive index of the lens material, the center thickness and the diameter. S3, Full-field ray tracing and optical performance calculation: The full-field principal ray cluster covering the daily rotation range of the human eye is obtained by reverse ray tracing. Combined with forward differential ray tracing, the optical performance parameters under each field of view are calculated. The optical performance parameters include meridional diopter, sagittal diopter, oblique astigmatism, field curvature, distortion and modulation transfer function (MTF). S4. Construct a multi-objective optimization evaluation function: Based on optical performance parameters, construct a weighted multi-objective evaluation function that includes astigmatism, field curvature, distortion, and MTF terms, and set the weight coefficient of each evaluation term according to the human eye's visual sensitivity. S5. Optimization of free torus surface based on simulated annealing algorithm: Using the surface parameters of the free torus surface as optimization variables and minimizing the evaluation function value as the objective, the simulated annealing algorithm is used for global iterative optimization to output the optimal surface parameters. S6. Surface Fitting and Machining Data Output: Fit the optimized discrete sampling point elevation data to obtain the complete free toroidal surface equation and output the surface data for CNC machining of lenses.

[0012] Preferably, step S1 specifically includes: a1. Based on clinical anatomical data of the human eye, determine the parameters of the lens-to-eye distance and the position of the center of rotation of the eyeball, wherein the lens-to-eye distance is set to 12mm and the distance from the anterior surface of the cornea to the center of rotation of the eyeball is set to 15mm. a2. Establish a global coordinate system with the eyeball rotation center as the origin and a lens coordinate system with the lens geometric center as the origin. Construct a lens-eye joint optical model that can simulate human eye rotation. The axial distance from the eyeball rotation center to the vertex of the rear surface of the lens is set to 27mm, and the human eye rotation field of view is set to -20° to +20° along the X and Y axes.

[0013] Preferably, in step S3, the reverse ray tracing specifically involves: starting from the center of eye rotation, tracing the principal rays passing through the rear and front surfaces of the lens to obtain the principal ray clusters corresponding to the sampling points of the entire field of view; the forward differential ray tracing specifically involves: constructing differential ray clusters for the principal rays of each field of view, accurately calculating the propagation path of the light at the refractive interface of the lens substrate, and solving for the optical performance parameters of each field of view.

[0014] Preferably, the multi-objective evaluation function is expressed as follows: in, f OAEis the astigmatism evaluation term for the entire field of view, and is the sum of squares of the oblique axis astigmatism for each field of view; f FC This is the evaluation term for the field curvature of the entire field of view, namely the sum of squares of the meridional and sagittal field curvatures of each field of view; f DIST This is the full field-of-view distortion evaluation term, which is the sum of squares of the relative distortion of each field of view; f MTF This is the MTF evaluation item for the entire field of view, which is the sum of squares of the differences between the measured MTF value and the target value at the set spatial frequency for each field of view; , , , These are the weighting coefficients for the corresponding evaluation items.

[0015] Preferably, the weight coefficient of the corresponding evaluation item =0.8, =0.5, =1.5, =2.0.

[0016] Preferably, in step S5, the optimization variables include the curvature in the X / Y directions of the biconical base, the conic coefficient, and the coefficients of higher-order terms of the XY polynomial; the simulated annealing algorithm uses exponential decay cooling and uses the Metropolis criterion to determine whether to accept the new solution after perturbation.

[0017] Preferably, the simulated annealing algorithm has an initial temperature of 100℃, a temperature decay coefficient of 0.95, an inner loop iteration count of 100, and a termination temperature of 1×10⁻⁶. -6 ℃.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention relates to a front-flat, free-form torus surface myopia correction lens for XR glasses and its manufacturing method. It significantly improves image quality and provides excellent consistency in sharpness across the entire field of view. Utilizing a front-flat, rear-curved structure combined with a free-form torus surface design, it overcomes the limitations of traditional spherical, aspherical, and torus surface lenses in terms of optimization freedom. This enables refined and coordinated correction of off-axis aberrations across the entire field of view, achieving improvements of 59.7% and 60.6% respectively compared to spherical lenses with the same parameters, and 34.8% and 35.6% respectively compared to commercially available conventional lenses. It effectively solves the problems of blurred and distorted peripheral vision associated with traditional lenses.

[0019] 2. The front-flat free-circuit myopia correction lens for XR glasses and its manufacturing method provide an excellent wearing experience. It performs optimally in core dimensions such as clarity, distortion control, dizziness suppression, and eye fatigue relief. Even after prolonged wear, it can maintain excellent visual comfort and significantly reduce the wearer's visual fatigue and discomfort.

[0020] 3. The front-flat free-form torus surface myopia correction lens for XR glasses and its manufacturing method significantly improve optimization efficiency and are suitable for industrialized personalized customization. It adopts simulated annealing algorithm for global optimization, which not only breaks through the dependence of traditional damped least squares method on initial values ​​and avoids getting trapped in local optima, but also greatly improves optimization efficiency, and can support rapid iterative design and large-scale personalized customization production of lenses.

[0021] 4. This front-flat free-form torus refractive lens for XR glasses and its manufacturing method significantly reduce surface reflection interference on the front surface of the lens compared to traditional forward-curved lenses, thus improving visual comfort. It also facilitates lens coating processing and quality inspection, effectively controls lens edge thickness, reduces lens weight, and enhances physical wearing comfort. Furthermore, the flat front surface can be directly adapted to the waveguide sheet bonding requirements of XR near-eye display devices, expanding its application scenarios for refractive lenses in near-eye display devices, thus broadening its application range. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the combined optical model of the lens and eye of the present invention; Figure 2 This is a schematic diagram of the manufacturing method of the present invention; Figure 3 This is a comparison chart of the full-field MTF of the present invention and a commercially available conventional lens at a spatial frequency of 100 lp / mm in a -7.00D myopia correction scenario in Embodiment 1 of the present invention. Figure 4 This is a comparison chart of the total human factor test scores for different lens design schemes of the present invention; In the diagram: 1. Lens matrix; 2. Anterior surface of the lens; 3. Posterior surface of the lens; 4. Cornea; 5. Aqueous humor; 6. Pupil; 7. Lens; 8. Vitreous humor; 9. Retina; 10. Center of rotation of the eyeball. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integrated connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0027] Example Please see Figure 1-4 As shown, the present invention provides a front-plane free-form torus surface myopia correction lens solution for XR glasses, comprising a lens substrate 1, wherein the lens substrate 1 is provided with a front surface 2 and a rear surface 3. The front surface 2 is configured as an optical plane; the rear surface 3 is configured as a free-form torus surface, which is configured with a biconical surface as a base and superimposed with higher-order terms of the XY polynomial, for simultaneously correcting defocus, astigmatism, field curvature, and distortion across the entire field of view. The lens substrate 1 also includes a central correction zone and a peripheral optimization zone surrounding the central correction zone. The central correction zone is used to accurately correct the wearer's myopia and astigmatism, and the peripheral optimization zone is used to correct optical aberrations in the off-axis field of view when the eyeball rotates.

[0028] The surface shape expression formula for a free torus is as follows: in, , These are the central curvatures in the X and Y directions, respectively. , These represent the conic coefficients in the X and Y directions, respectively. , Let these be the coefficients of the higher-order terms of the XY polynomial.i Let N be the order of the higher-order term, and N be the highest order of the higher-order term, where N≥1.

[0029] To address the need for -7.00D simple myopia correction, this invention also provides a method for manufacturing a front-flat free-form torus refractive lens for XR glasses. The manufacturing method specifically includes: S1. Construct a lens-eye combined optical model, which includes cornea 4, aqueous humor 5, pupil 6, lens 7, vitreous body 8, retina 9, eyeball rotation center 10, anterior surface of lens 2, and posterior surface of lens 3. a1. Based on clinical anatomical data of the human eye, determine the parameters of the lens-to-eye distance and the position of the eye rotation center 10, wherein the lens-to-eye distance is set to 12mm and the distance from the anterior surface of the cornea 4 to the eye rotation center 10 is set to 15mm. a2. Establish a global coordinate system with the eye rotation center 10 as the origin and a lens coordinate system with the lens geometric center as the origin. Construct a lens-eye joint optical model that can simulate human eye rotation. The axial distance from the eye rotation center 10 to the three vertices of the lens rear surface is set to 27mm. The human eye rotation field of view is set to -20° to +20° along the X and Y axes. A sampling interval is set every 4°, with a total of 121 field of view sampling points, covering the core scenarios of human eye daily vision. S2. Define the basic structure and parameters of the lens: Set the front surface 2 of the lens as the optical plane, and determine the basic optical parameters of the lens. The basic optical parameters include the spherical power, cylindrical power, axis to be corrected, the refractive index of the lens material, the center thickness, and the diameter. The lens uses an optical resin material with a refractive index of 1.67, a nominal diameter of 70 mm, and a center thickness of 1.2 mm. Set the front surface 2 of the lens as the optical plane, and the surface profile sagitta is 0. The rear surface is the free torus surface to be optimized, and the initial surface profile is a sphere corresponding to -7.00D, which is used as the initial value for optimization. S3. Full-field ray tracing and optical performance calculation: A full-field principal ray cluster covering the daily rotation range of the human eye is obtained through inverse ray tracing. Combined with forward differential ray tracing, optical performance parameters for each field of view are calculated. These parameters include meridional diopter, sagittal diopter, oblique astigmatism, field curvature, distortion, and modulation transfer function (MTF). Specifically, inverse ray tracing involves starting from the eye rotation center 10 and tracing the principal rays passing through the rear surface 3 and the front surface 2 of the lens to obtain the principal ray cluster corresponding to the full-field sampling point. Forward differential ray tracing involves constructing differential ray clusters for the principal rays in each field of view, accurately calculating the propagation path of the light at the refraction interface of the lens substrate 1, and solving for the optical performance parameters of each field of view. S4. Constructing a multi-objective optimization evaluation function: Based on optical performance parameters, construct a weighted multi-objective evaluation function including astigmatism, field curvature, distortion, and MTF terms. Set the weight coefficient for each evaluation term according to human visual sensitivity. The formula for the multi-objective evaluation function is as follows: in, f OAE This is the evaluation term for astigmatism across the entire field of view, which is the sum of squares of the oblique axis astigmatism across each field of view; f FC This is the evaluation term for the field curvature of the entire field of view, namely the sum of squares of the meridional and sagittal field curvatures of each field of view; f DIST This is the full field-of-view distortion evaluation term, which is the sum of squares of the relative distortion of each field of view; f MTF This is the MTF evaluation item for the entire field of view, which is the sum of squares of the differences between the measured MTF value and the target value at the set spatial frequency for each field of view; , , , The weight coefficients for the corresponding evaluation items. =0.8, =0.5, =1.5, =2.0; S5. Optimization of Free-Form Torus Surfaces Based on Simulated Annealing Algorithm: The surface parameters of the free-form torus surface are used as optimization variables, including the X / Y curvature of the biconical base, the conic coefficient, and the coefficients of eight higher-order terms of the 4th-order XY polynomial. A simulated annealing algorithm is used for global iterative optimization to output the optimal surface parameters. The simulated annealing algorithm employs exponential decay cooling, and the Metropolis criterion is used to determine whether to accept the new solution after perturbation. The initial temperature of the simulated annealing algorithm is set to 100℃, the temperature decay coefficient is set to 0.95, the number of inner loop iterations is set to 100, and the termination temperature is 1×10⁻⁶. -6 ℃, with a maximum number of iterations of 1000; The optimization process involves: randomly generating initial optimization variables and calculating the initial evaluation function value E; applying random perturbations to the optimization variables in each iteration to generate a new solution and calculating the evaluation function value E′ of the new solution; if ΔE = E′-E ≤ 0, the new solution is directly accepted; if ΔE>0, the new solution is accepted with probability exp (-ΔE / T) according to the Metropolis criterion; after completing the inner loop, the temperature is reduced, and the next iteration begins until the termination condition is met, at which point the optimal surface parameters are output. The total optimization time is approximately 70 seconds, significantly improving efficiency compared to the 230 seconds of the traditional genetic algorithm. The surface fitting and machining data output process uses the optimized full-field discrete sampling point elevation data to perform surface fitting using the least squares method, obtaining the complete free-form torus surface equation and outputting G-code and standardized surface data files suitable for CNC lathe machining.

[0030] S6. Surface Fitting and Machining Data Output: Fit the optimized discrete sampling point elevation data to obtain the complete free toroidal surface equation and output the surface data for CNC machining of lenses.

[0031] Furthermore, the lens of this invention, designated as Design D, was compared with three other conventional lens designs (Designs A, B, and C) in a human factor comparison test. Thirty subjects were recruited for the test, with myopia ranging from -0.25D to -9.00D and astigmatism ≤ -2.50D. Short-term wear tests of 10 minutes and long-term wear tests of 60 minutes were conducted. The test scoring dimensions included wearing comfort, clarity, distortion, chromatic aberration, eye fatigue, and dizziness, with corresponding weights of 10%, 20%, 15%, 5%, 25%, and 25%, respectively, for a maximum score of 5 points. The test results are as follows: After 10 minutes of short-term wear, Design D scored 4.15 points, ranking first. It established the optimal initial wearing experience with the highest clarity and lowest dizziness. After 60 minutes of long-term wear, Design D still scored 3.90 points, maintaining its first-place ranking, with only a 0.25-point decrease compared to the short-term wear, indicating minimal performance degradation and excellent long-term stability. Compared to other designs, Design C scored 3.89 points with a 0.20-point decrease, but its overall score was still lower than Design D. Designs B and A scored 3.67 and 3.51 points respectively, with decreases of 0.34 and 0.39 points respectively, indicating a significant decline in long-term wearing experience. Detailed dimension tests show that after 60 minutes of long-term wear, Design D achieved the highest scores in clarity and distortion, with a score of 3.86 in eye fatigue and 3.64 in dizziness, all significantly better than other designs. This fully verifies the excellent comfort and visual stability of this invention in long-term wearing scenarios.

[0032] After optimization and testing, the front-flat free-form torus lens obtained in this embodiment not only achieves precise astigmatism correction in the central field of vision, but also effectively corrects oblique astigmatism and distortion in the peripheral off-axis field of vision. Human factors test results show that the wearer's dynamic visual distortion and dizziness are significantly reduced, and the eye fatigue problem caused by wearing it for a long time is significantly relieved. The overall wearing experience is far superior to traditional torus astigmatic lenses.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A front-flat free-form torus refractive lens for XR glasses, comprising a lens substrate (1), characterized in that: The lens substrate (1) is provided with a front surface (2) and a rear surface (3). The front surface (2) is set as an optical plane; the rear surface (3) is set as a free torus surface. The free torus surface is set with a biconical surface as the base and superimposed with higher-order terms of XY polynomials, which are used to simultaneously correct defocus, astigmatism, field curvature and distortion in the entire field of view.

2. The front-flat free-form torus refractive lens for XR glasses according to claim 1, characterized in that: The surface shape expression formula for the free torus is: in, , These are the central curvatures in the X and Y directions, respectively. , These represent the conic coefficients in the X and Y directions, respectively. , Let these be the coefficients of the higher-order terms of the XY polynomial. i Let N be the order of the higher-order term, and N be the highest order of the higher-order term, where N≥1.

3. The front-flat free-form torus refractive lens for XR glasses according to claim 1, characterized in that: The lens substrate (1) also includes a central correction zone and a peripheral optimization zone surrounding the central correction zone. The central correction zone is used to accurately correct the wearer's myopia and astigmatism, and the peripheral optimization zone is used to correct the optical aberrations of the off-axis field of view when the eyeball rotates.

4. The method for manufacturing a front-flat free-form torus refractive lens for XR glasses according to any one of claims 1-3, characterized in that: The manufacturing method specifically includes: S1. Construct a lens-eye combined optical model, which includes the cornea (4), aqueous humor (5), pupil (6), lens (7), vitreous body (8), retina (9), center of rotation of the eyeball (10), anterior surface of the lens (2) and posterior surface of the lens (3). S2. Define the basic structure and parameters of the lens: Set the front surface (2) of the lens as the optical plane, and determine the basic optical parameters of the lens. The basic optical parameters include the spherical power, cylindrical power, axis to be corrected, the refractive index of the lens material, the center thickness and the diameter. S3, Full-field ray tracing and optical performance calculation: The full-field principal ray cluster covering the daily rotation range of the human eye is obtained by reverse ray tracing. Combined with forward differential ray tracing, the optical performance parameters under each field of view are calculated. The optical performance parameters include meridional diopter, sagittal diopter, oblique astigmatism, field curvature, distortion and modulation transfer function (MTF). S4. Construct a multi-objective optimization evaluation function: Based on optical performance parameters, construct a weighted multi-objective evaluation function that includes astigmatism, field curvature, distortion, and MTF terms, and set the weight coefficient of each evaluation term according to the human eye's visual sensitivity. S5. Optimization of free torus surface based on simulated annealing algorithm: Using the surface parameters of the free torus surface as optimization variables and minimizing the evaluation function value as the objective, the simulated annealing algorithm is used for global iterative optimization to output the optimal surface parameters. S6. Surface Fitting and Machining Data Output: Fit the optimized discrete sampling point elevation data to obtain the complete free toroidal surface equation and output the surface data for CNC machining of lenses.

5. The method for manufacturing a front-flat free-form torus refractive lens for XR glasses according to claim 4, characterized in that: Step S1 specifically includes: a1. Based on clinical anatomical data of the human eye, determine the parameters of the lens-to-eye distance and the position of the eye rotation center (10), wherein the lens-to-eye distance is set to 12mm and the distance from the anterior surface of the cornea (4) to the eye rotation center (10) is set to 15mm. a2. Establish a global coordinate system with the eye rotation center (10) as the origin and a lens coordinate system with the lens geometric center as the origin. Construct a lens-eye joint optical model that can simulate human eye rotation. The axial distance from the eye rotation center (10) to the vertex of the lens rear surface (3) is set to 27mm, and the human eye rotation field of view is set to -20° to +20° along the X and Y axes.

6. The method for manufacturing a front-flat free-form torus refractive lens for XR glasses according to claim 4, characterized in that: In step S3, the reverse ray tracing specifically involves: starting from the eye rotation center (10), tracing the principal rays passing through the rear surface (3) and front surface (2) of the lens to obtain the principal ray clusters corresponding to the sampling points of the entire field of view; the forward differential ray tracing specifically involves: constructing differential ray clusters for the principal rays of each field of view, accurately calculating the propagation path of the light at the refraction interface of the lens substrate (1), and solving for the optical performance parameters of each field of view.

7. The method for manufacturing a front-flat free-form torus refractive lens for XR glasses according to claim 4, characterized in that: The multi-objective evaluation function is expressed as follows: in, f OAE This is the evaluation term for astigmatism across the entire field of view, which is the sum of squares of the oblique axis astigmatism across each field of view; f FC This is the evaluation term for the field curvature of the entire field of view, namely the sum of squares of the meridional and sagittal field curvatures of each field of view; f DIST This is the full field-of-view distortion evaluation term, which is the sum of squares of the relative distortion of each field of view; f MTF This is the MTF evaluation item for the entire field of view, which is the sum of squares of the differences between the measured MTF value and the target value at the set spatial frequency for each field of view; , , , These are the weighting coefficients for the corresponding evaluation items.

8. The method for manufacturing a front-flat free-form torus refractive lens for XR glasses according to claim 7, characterized in that: The weight coefficient of the corresponding evaluation item =0.8, =0.5, =1.5, =2.

0.

9. The method for manufacturing a front-flat free-form torus refractive lens for XR glasses according to claim 4, characterized in that: In step S5, the optimization variables include the curvature in the X / Y directions of the biconical base, the conic coefficients, and the coefficients of higher-order terms of the XY polynomial; the simulated annealing algorithm uses exponential decay cooling and uses the Metropolis criterion to determine whether to accept the new solution after perturbation.

10. The method for manufacturing a front-flat free-form torus refractive lens for XR glasses according to claim 4, characterized in that: The simulated annealing algorithm has an initial temperature of 100℃, a temperature decay coefficient of 0.95, an inner loop iteration count of 100, and a termination temperature of 1×10⁻⁶. -6 ℃.

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