Progressive multi-focus optical correction method based on peripheral defocus principle

Abstract

The invention discloses a peripheral defocus principle-based progressive multi-focus optical correction method, which belongs to the technical field of vision correction and comprises the following steps of S1, collecting eye data of teenagers; s2, eye biological parameters are extracted; s3, calculating the change relation between the center defocusing amount and the peripheral defocusing amount under the dynamic change of different field angles and different pupil diameters; s4, presetting a target center defocusing amount and a peripheral defocusing amount of the progressive multi-focus lens under different field angles and different pupil diameter dynamic changes, and calculating a difference value between the target center defocusing amount and the peripheral defocusing amount under different field angles and different pupil diameter dynamic changes of eyes as a to-be-adjusted defocusing amount; s5, calculating parameters of the progressive multi-focus lens; s6, constructing a progressive multi-focus lens model; s7, optimizing the progressive multi-focus lens model; s8, performing optical correction by using the optimized progressive multi-focus lens model; the traditional Chinese medicine composition has a treatment effect and a prevention and control effect at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of vision correction, and in particular relates to a progressive multifocal optical correction method based on the principle of peripheral defocus. Background Art

[0002] With the popularization of electronic devices, the incidence of myopia has gradually increased. It not only causes many inconveniences to people's daily life, study and work, but also may cause a series of serious eye complications including retinal detachment and glaucoma, posing a great threat to eye health. Therefore, myopia treatment is particularly important.

[0003] The current treatment for myopia generally involves measuring the degree of myopia and wearing glasses with appropriate degrees based on the measured eye degree. This treatment method can only help myopic people see objects clearly and has no preventive and control effect.

[0004] In view of this, a progressive multifocal optical correction method based on the peripheral defocus principle is designed to solve the above problems. Summary of the Invention

[0005] In order to solve the problems raised in the above background technology, the present invention provides a progressive multifocal optical correction method based on the principle of peripheral defocus, which has the characteristics of being able to achieve both therapeutic and preventive effects.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a progressive multifocal optical correction method based on the principle of peripheral defocus, comprising the following steps:

[0007] S1: Collect eye data of adolescents;

[0008] S2: Extracting ocular biometric parameters from adolescent eye data;

[0009] S3: By extracting eye biological parameters, calculate the changing relationship between central defocus and peripheral defocus under different field of view angles and different pupil diameter dynamic changes;

[0010] S4: Preset the target central defocus amount and peripheral defocus amount of the progressive multifocal lens under different field angles and different pupil diameters, and calculate the difference between the central defocus amount and peripheral defocus amount under different field angles and different pupil diameters of the eye as the defocus amount to be adjusted;

[0011] S5: Calculating parameters of the progressive addition lens according to the defocus amount to be adjusted;

[0012] S6: Construct a progressive addition lens model;

[0013] S7: optimizing the progressive multifocal lens model by minimizing the progressive multifocal lens model and the calculated progressive multifocal lens parameters as an optimization goal;

[0014] S8: Optical correction with an optimized progressive addition lens model.

[0015] Furthermore, the specific steps of step S2 include:

[0016] The anterior corneal curvature radius, posterior corneal curvature radius, corneal thickness, corneal refractive index, anterior lens curvature radius, posterior lens curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness, retinal refractive index, field of view angle, and pupil diameter were extracted from the adolescent eye data.

[0017] Furthermore, the specific steps of step S3 include:

[0018] The extracted corneal anterior surface curvature radius, corneal posterior surface curvature radius, corneal thickness, corneal refractive index, lens anterior surface curvature radius, lens posterior surface curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness, retinal refractive index, field of view angle and pupil diameter are input into the eyeball model;

[0019] Constructing ray tracing operators by extending matrix optics;

[0020] The constructed ray tracing operator is used to calculate the refraction of each incident ray at each interface of the human eye;

[0021] The propagation path of the incident light is obtained according to the refraction of the incident light;

[0022] The extracted corneal anterior surface curvature radius, corneal posterior surface curvature radius, corneal thickness, corneal refractive index, lens anterior surface curvature radius, lens posterior surface curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness and retinal refractive index are used as the final propagation endpoint of the incident light as the imaging position of the retina at the central field angle;

[0023] The extracted corneal anterior surface curvature radius, corneal posterior surface curvature radius, corneal thickness, corneal refractive index, lens anterior surface curvature radius, lens posterior surface curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness, retinal refractive index, field of view angle and pupil diameter are used as the final propagation endpoint of the incident light as the imaging position of the retina at different field of view angles and different pupil diameters;

[0024] Calculate the central defocus amount by the imaging position of the retina at the central field angle;

[0025] Calculate the peripheral defocus amount by the imaging position of the retina at different field angles and pupil diameters;

[0026] The relationship between the central defocus and the peripheral defocus at different field of view angles and pupil diameters is calculated under dynamic changes of different field of view angles and pupil diameters.

[0027] Furthermore, the specific steps of step S4 include:

[0028] Preset the central defocus value of the progressive multifocal lens under the central field of view angle;

[0029] By analyzing the relationship between the central defocus and the peripheral defocus under different field angles and different pupil diameters, the peripheral defocus under different field angles and different pupil diameters of the preset progressive multifocal lens is calculated;

[0030] The defocus amount to be adjusted is calculated by combining the central defocus amount of the eyeball with the peripheral defocus amount under dynamic changes in different field of view angles and different pupil diameters, as well as the central defocus amount preset by the progressive multifocal lens with the peripheral defocus amount under dynamic changes in different field of view angles and different pupil diameters.

[0031] Furthermore, the specific steps of step S5 include:

[0032] The average curvature of the progressive addition lens is calculated based on the defocus amount to be adjusted.

[0033] Furthermore, the specific steps of step S6 include:

[0034] Characterize the surface of progressive multifocal lens by Zernike polynomials:

[0035]

[0036] Where: z(r,φ) represents the height of the lens surface under the polar coordinate (r,φ); c i represents the polynomial coefficients;

[0037] Z i (r,φ) represents the i-th Zernike polynomial;

[0038] The average curvature on the surface of the progressive addition lens characterized by Zernike polynomials:

[0039]

[0040] Where: z r represents the first-order partial derivative of the lens surface height z(r,φ) with respect to the radial coordinate r in polar coordinates, describing the rate of change of z with r; φ represents the first-order partial derivative of the lens surface height z(r,φ) with respect to the azimuth angle φ in polar coordinates, describing the rate of change of z with φ; rrrepresents the second-order partial derivative, describing z r The rate of change of r; z φφ represents the second-order partial derivative, describing z φ The rate of change of z with φ; rφ Represents the mixed partial derivative of the lens surface height z(r,φ) with respect to r and φ in polar coordinates, describing z r The rate of change of φ or z φ The rate of change of r.

[0041] Furthermore, the specific steps of step S7 include:

[0042] Initialize a set of Zernike polynomial coefficients;

[0043] Calculate the surface height of the progressive addition lens based on the current Zernike polynomial coefficients;

[0044] Calculate the first and second order partial derivatives of the surface height of progressive addition lenses with respect to radial coordinates and azimuth angles;

[0045] Substitute the first and second order partial derivatives into the mean curvature formula to get the current mean curvature;

[0046] Calculate the difference between the current mean curvature and the desired mean curvature;

[0047] The Zernike polynomial coefficients are optimized using a preset optimization rule to minimize the difference between the current mean curvature and the desired mean curvature.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The present invention uses the principle of peripheral defocus in conjunction with progressive multifocal lenses to cause myopic defocus in the peripheral retina. That is, when the imaging position is in front of the retina, it can effectively inhibit the excessive growth of the eye axis through a specific feedback mechanism, thereby slowing down the progression of myopia. Compared with the existing technology, it can achieve both therapeutic and preventive effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0052] The present invention provides the following technical solution: a progressive multifocal optical correction method based on the principle of peripheral defocus, comprising the following steps:

[0053] S1: Collect eye data of adolescents;

[0054] S2: Extracting ocular biometric parameters from adolescent eye data;

[0055] S3: By extracting eye biological parameters, calculate the changing relationship between central defocus and peripheral defocus under different field of view angles and different pupil diameter dynamic changes;

[0056] S4: Preset the target central defocus amount and peripheral defocus amount of the progressive multifocal lens under different field angles and different pupil diameters, and calculate the difference between the central defocus amount and peripheral defocus amount under different field angles and different pupil diameters of the eye as the defocus amount to be adjusted;

[0057] S5: Calculating parameters of the progressive addition lens according to the defocus amount to be adjusted;

[0058] S6: Construct a progressive addition lens model;

[0059] S7: optimizing the progressive multifocal lens model by minimizing the progressive multifocal lens model and the calculated progressive multifocal lens parameters as an optimization goal;

[0060] S8: Optical correction with an optimized progressive addition lens model.

[0061] Specifically, the steps of step S1 include:

[0062] Collect CT / MRI data of the eyes of adolescents.

[0063] Specifically, the specific steps of step S2 include:

[0064] Extracting ocular biometric parameters from collected adolescent ocular CT / MRI data Among them, r i represents the curvature radius of the i-th interface, h i represents the thickness of the i-th medium, n i represents the refractive index of the i-th medium, θ i represents the interface inclination angle, d i represents the pupil diameter, i=1,2,3,4,5, 1 represents the anterior surface of the cornea, 2 represents the posterior surface of the cornea, 3 represents the anterior surface of the lens, 4 represents the posterior surface of the lens, and 5 represents the retina.

[0065] Specifically, the specific steps of step S3 include:

[0066] The extracted eye biological parameters Enter the Liou-Brennan model;

[0067] The extracted eye biological parameters Enter the Liou-Brennan model;

[0068] The ray tracing operator is constructed by extending matrix optics, and the expression is:

[0069]

[0070] Where: R i represents the refraction matrix; T i represents the transmission matrix;

[0071]

[0072] Where: n i represents the refractive index of the medium in front of the i-th refractive surface; n i ' represents the refractive index of the medium behind the i-th refractive surface; r i represents the curvature radius of the i-th interface;

[0073]

[0074] Where: d i represents the thickness of the i-th medium; n i represents the refractive index of the i-th medium;

[0075] By constructing a ray tracing operator, each incident ray is calculated Refraction at various interfaces of the human eye

[0076] According to the incident light The propagation path of the incident light is obtained by the refraction situation;

[0077] Eye biological parameters Incident light The final propagation endpoint is the imaging position p of the retina at the central visual field angle. i1 =[x i1 ,y i1 ];

[0078] Eye biological parameters Incident light The last propagation endpoint is used as the imaging position p of the retina with different field angles and different pupil diameters. i2 =[x i2 ,y i2 ];

[0079] Through the central field angle θ i1 The retinal imaging position pi1 =[x i1 ,y i1 ], calculate the center defocus amount ΔD i1 :

[0080]

[0081] Where: p i1 Indicates the central field of view angle θ i1 Retinal imaging position; p i1 ' represents the central field angle θ i1 The ideal retinal imaging position is the preset value;

[0082] Through different field angles θ in and different pupil diameters d in The retinal imaging position p i2 =[x i2 ,y i2 ], calculate the peripheral defocus amount ΔD i2 :

[0083]

[0084] Where: p i2 Indicates different field of view angles θ in and different pupil diameters d in Retinal imaging position; p i2 ' represents different viewing angles θ in and different pupil diameters d in The ideal retinal imaging position is the preset value;

[0085] Defocus amount ΔD through the center i1 And different field angles θ in and different pupil diameters d in Peripheral defocus ΔD i2 , calculate different field of view angles θ in and different pupil diameters d in Under dynamic changes, the center defocus amount ΔD i1 Defocus amount ΔD i2 The changing relationship:

[0086] ΔD(θ,α,β,d)=(1-w(d))·ΔD i1 +w(d)·ΔD i2 (θ,α,β)

[0087] Where: θ represents the field of view angle; α represents the rotation angle around the y-axis; β represents the rotation angle around the x-axis; d represents the pupil diameter; w(d) represents the pupil weighting function; ΔD i1 Indicates the center defocus amount; ΔD i2Indicates the peripheral defocus amount;

[0088] The pupil weighting function w(d) is expressed as:

[0089]

[0090] Where: d represents the pupil diameter.

[0091] Specifically, the specific steps of step S4 include:

[0092] Preset progressive multifocal lens center field angle θ i1 The center defocus amount ΔD under i1 ;

[0093] Through different field angles θ in and different pupil diameters d in Under dynamic changes, the center defocus amount ΔD i1 Defocus amount ΔD i2 The change relationship of θ is calculated to meet the different field angles of the preset progressive multifocal lens. in and different pupil diameters d in Dynamically changing peripheral defocus ΔD i2 ;

[0094] Defocus amount ΔD through the center of the eyeball i1 With different field angles θ in and different pupil diameters d in Dynamically changing peripheral defocus ΔD i2 And the center defocus amount ΔD preset for progressive multifocal lenses i1 With different field angles θ in and different pupil diameters d in Dynamically changing peripheral defocus ΔD i2 , calculate the defocus amount ΔD to be adjusted.

[0095] Specifically, the specific steps of step S5 include:

[0096] Calculate the average curvature H of the progressive addition lens based on the defocus amount ΔD to be adjusted:

[0097]

[0098] Where: ΔD represents the defocus amount to be adjusted; n represents the refractive index of the progressive addition lens, which is a known value.

[0099] Specifically, the specific steps of step S6 include:

[0100] Characterize the surface of progressive multifocal lens by Zernike polynomials:

[0101]

[0102] Where: z(r,φ) represents the height of the lens surface under the polar coordinate (r,φ); c i represents the polynomial coefficients;

[0103] Z i (r,φ) represents the i-th Zernike polynomial;

[0104] The average curvature H(r,φ) on the surface of a progressive addition lens characterized by Zernike polynomials is:

[0105]

[0106] Where: z r represents the first-order partial derivative of the lens surface height z(r,φ) with respect to the radial coordinate r in polar coordinates, describing the rate of change of z with r; φ represents the first-order partial derivative of the lens surface height z(r,φ) with respect to the azimuth angle φ in polar coordinates, describing the rate of change of z with φ; rr represents the second-order partial derivative, describing z r The rate of change of r; z φφ represents the second-order partial derivative, describing z φ The rate of change of z with φ; rφ Represents the mixed partial derivative of the lens surface height z(r,φ) with respect to r and φ in polar coordinates, describing z r The rate of change of φ or z φ The rate of change of r.

[0107] Specifically, the specific steps of step S7 include:

[0108] Initialize a set of Zernike polynomial coefficients c i ;

[0109] According to the current Zernike polynomial coefficient c i , calculate the surface height function z(r,φ) of the progressive multifocal lens;

[0110] Calculate the first and second order partial derivatives z of the surface height function z(r,φ) of the progressive multifocal lens with respect to the radial coordinate r and the azimuth angle φ r 、z φ 、z rr 、z φφ and z rφ ;

[0111] The first and second order partial derivatives z r 、z φ 、z rr 、z φφ and z rφSubstitute the mean curvature H(r,φ) to obtain the current mean curvature H(r,φ);

[0112] Calculate the difference between the current mean curvature H(r,φ) and the desired mean curvature H;

[0113] The Zernike polynomial coefficient c is optimized by the preset optimization rule. i The optimization is performed to minimize the difference between the current mean curvature H(r,φ) and the desired mean curvature H.

[0114] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A progressive multifocal optical correction method based on the principle of peripheral defocus, characterized in that: The following steps are involved: S1: Collect eye data of adolescents; S2: Extracting ocular biometric parameters from adolescent eye data; S3: By extracting eye biological parameters, calculate the changing relationship between central defocus and peripheral defocus under different field of view angles and different pupil diameter dynamic changes; S4: Preset the target central defocus amount and peripheral defocus amount of the progressive multifocal lens under different field angles and different pupil diameters, and calculate the difference between the central defocus amount and peripheral defocus amount under different field angles and different pupil diameters of the eye as the defocus amount to be adjusted; S5: Calculating parameters of the progressive addition lens according to the defocus amount to be adjusted; S6: Construct a progressive addition lens model; S7: optimizing the progressive multifocal lens model by minimizing the progressive multifocal lens model and the calculated progressive multifocal lens parameters as an optimization goal; S8: Optical correction with an optimized progressive addition lens model.

2. The progressive addition optical correction method based on the peripheral defocus principle according to claim 1, characterized in that: The specific steps of step S2 include: The anterior corneal curvature radius, posterior corneal curvature radius, corneal thickness, corneal refractive index, anterior lens curvature radius, posterior lens curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness, retinal refractive index, field of view angle, and pupil diameter were extracted from the adolescent eye data.

3. The progressive addition optical correction method based on the peripheral defocus principle according to claim 2, characterized in that: The specific steps of step S3 include: The extracted corneal anterior surface curvature radius, corneal posterior surface curvature radius, corneal thickness, corneal refractive index, lens anterior surface curvature radius, lens posterior surface curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness, retinal refractive index, field of view angle and pupil diameter are input into the eyeball model; Constructing ray tracing operators by extending matrix optics; The constructed ray tracing operator is used to calculate the refraction of each incident ray at each interface of the human eye; The propagation path of the incident light is obtained according to the refraction of the incident light; The extracted corneal anterior surface curvature radius, corneal posterior surface curvature radius, corneal thickness, corneal refractive index, lens anterior surface curvature radius, lens posterior surface curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness and retinal refractive index are used as the final propagation endpoint of the incident light as the imaging position of the retina at the central field angle; The extracted corneal anterior surface curvature radius, corneal posterior surface curvature radius, corneal thickness, corneal refractive index, lens anterior surface curvature radius, lens posterior surface curvature radius, lens thickness, lens refractive index, retinal curvature radius, retinal thickness, retinal refractive index, field of view angle and pupil diameter are used as the final propagation endpoint of the incident light as the imaging position of the retina with different field of view angles and different pupil diameters; Calculate the central defocus amount by the imaging position of the retina at the central field angle; Calculate the peripheral defocus amount by the imaging position of the retina at different field angles and pupil diameters; The relationship between the central defocus and the peripheral defocus at different field of view angles and pupil diameters is calculated under dynamic changes of different field of view angles and pupil diameters.

4. The progressive addition optical correction method based on the peripheral defocus principle according to claim 3, characterized in that: The specific steps of step S4 include: Preset the central defocus value of the progressive multifocal lens under the central field of view angle; By analyzing the relationship between the central defocus and the peripheral defocus under different field angles and different pupil diameters, the peripheral defocus under different field angles and different pupil diameters of the preset progressive multifocal lens is calculated; The defocus amount to be adjusted is calculated by combining the central defocus amount of the eyeball with the peripheral defocus amount under dynamic changes in different field of view angles and different pupil diameters, as well as the central defocus amount preset by the progressive multifocal lens with the peripheral defocus amount under dynamic changes in different field of view angles and different pupil diameters.

5. The progressive addition optical correction method based on the peripheral defocus principle according to claim 4, characterized in that: The specific steps of step S5 include: The average curvature of the progressive addition lens is calculated based on the defocus amount to be adjusted.

6. The progressive addition optical correction method based on the peripheral defocus principle according to claim 5, characterized in that: The specific steps of step S6 include: Characterize the surface of progressive multifocal lens by Zernike polynomials: Where: z(r,φ) represents the height of the lens surface under the polar coordinate (r,φ); c i represents the polynomial coefficients; Z i (r,φ) represents the i-th Zernike polynomial; The average curvature on the surface of the progressive addition lens characterized by Zernike polynomials: Where: z r represents the first-order partial derivative of the lens surface height z(r,φ) with respect to the radial coordinate r in polar coordinates, describing the rate of change of z with r; φ represents the first-order partial derivative of the lens surface height z(r,φ) with respect to the azimuth angle φ in polar coordinates, describing the rate of change of z with φ; rr represents the second-order partial derivative, describing z r The rate of change of r; z φφ represents the second-order partial derivative, describing z φ The rate of change of z with φ; rφ Represents the mixed partial derivative of the lens surface height z(r,φ) with respect to r and φ in polar coordinates, describing z r The rate of change of φ or z φ The rate of change of r.

7. The progressive addition optical correction method based on the peripheral defocus principle according to claim 6, characterized in that: The specific steps of step S7 include: Initialize a set of Zernike polynomial coefficients; Calculate the surface height of the progressive addition lens based on the current Zernike polynomial coefficients; Calculate the first and second order partial derivatives of the surface height of progressive addition lenses with respect to radial coordinates and azimuth angles; Substitute the first and second order partial derivatives into the mean curvature formula to get the current mean curvature; Calculate the difference between the current mean curvature and the desired mean curvature; The Zernike polynomial coefficients are optimized using a preset optimization rule to minimize the difference between the current mean curvature and the desired mean curvature.

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