A Design Method of Progressive Multifocal Ophthalmic Lens Based on Genetic Algorithm

A progressive multi-focal and genetic algorithm technology, applied in the field of optimal design of progressive multi-focal ophthalmic lenses, can solve difficult, time-consuming and laborious problems such as optimal parameters, and achieve overcoming limitations, time-saving and labor-saving design, and overall design The effect of features

Active Publication Date: 2019-04-02
SUZHOU UNIV OF SCI & TECH
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  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention aims at the problems of time-consuming and labor-intensive optimization design of existing progressive multi-focal ophthalmic lenses and the disadvantages that the optimal parameters are not easy to obtain, and provides a progressive multi-focal eye lens that can better suit the needs and preferences of the wearer. lens design method

Method used

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  • A Design Method of Progressive Multifocal Ophthalmic Lens Based on Genetic Algorithm
  • A Design Method of Progressive Multifocal Ophthalmic Lens Based on Genetic Algorithm
  • A Design Method of Progressive Multifocal Ophthalmic Lens Based on Genetic Algorithm

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Experimental program
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Embodiment 1

[0031]In this embodiment, an internal progressive multifocal lens with an addition power of 2 diopters is designed according to the needs of the spectacle wearer. The refractive index of the lens material is 1.532, and the diameter of the lens is φ=72mm. vision. The designed focal power of the inner surface distance zone Φ PA It is 4 diopters; the focal power of the near zone is Φ PB It is 2 diopters; the length of the gradient channel h=30 mm; the distance between the reference point A and the center point of the far zone L=15mm.

[0032] According to the technical solution disclosed in the Chinese invention patent CN103246080A, in the Cartesian coordinate system, the contour line cluster on the surface of the progressive multifocal lens Satisfy the Laplace equation of the following formula (1):

[0033] (1)

[0034] After determining the boundary conditions, the contour cluster can be obtained by solving the Laplace equation numerically. According to the technology ...

Embodiment 2

[0067] In this embodiment, the wearer requires that the progressive multifocal lens is suitable for office use, and other parameters are the same as in Embodiment 1. For this reason, in this example, the lens area is divided according to indoor office use, and the weighting coefficients of the near area, gradient channel, and low astigmatism area are set to relatively large values; and in order to reduce the astigmatism on both sides of the channel and near the near area, increase Weighting factor for maximum astigmatism. The weighting coefficients in the objective function formula (3) of each selected area As shown in table 2.

[0068] Table 2 Table of weighting coefficients in the objective function

[0069] .

[0070] Through the same genetic evolution process as in Example 1, the u value on the boundary of the contour line distribution u(x, y) is obtained as Figure 6 shown. The three-dimensional grid diagram of the contour line u(x,y) obtained by solving the diffe...

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Abstract

The invention discloses a method for designing progressive multifocal ophthalmic lenses based on a genetic algorithm. According to the demand of a glasses wearer, one or more characteristics of the progressive multi-focus eye lenses are determined to set an objective function, best boundary conditions conforming to a set target and related to a contour cluster u(x,y) Laplace equation are automatically searched by using the genetic algorithm, a contour cluster is solved through numerical calculation of the Laplace equation, and then the progressive multifocal ophthalmic lenses are further designed. The designed progressive multifocal ophthalmic lenses are in accordance with the requirements of the glasses wearer. The method overcomes the limitation of the form and the parameters of artificial selection of boundary conditions, makes the design save time and labor, and is more flexible and global.

Description

technical field [0001] The invention relates to a design method for progressive multifocal ophthalmic lenses, in particular to a method for automatically searching for the best boundary conditions through a genetic algorithm, and using a numerical method to solve the Laplace equation to design contour line clusters, so as to obtain a lens with a lens that meets the needs of the lens wearer. An optimal design method for characteristic progressive multifocal ophthalmic lenses. Background technique [0002] Progressive multifocal ophthalmic lenses can meet the needs of distance vision and near vision at the same time, and avoid the defects of bifocal lenses such as visual breakage when switching from distance vision to near vision. See attached figure 1 , which is a schematic diagram of different functional types of progressive multifocal ophthalmic lenses, represented by figure 1 It can be seen that the surface of the lens is divided into five types of areas: the far zone, t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G02C7/02G02C7/06
CPCG02C7/028G02C7/061
Inventor 唐运海吴泉英
Owner SUZHOU UNIV OF SCI & TECH
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