渐进多焦点镜片面形误差与光焦度关系的分析

渐进多焦点眼镜片能够同时满足视远与视近的需求,其应用日益广泛.本文介绍了渐进多焦点镜片的设计与评价方法,在此基础上通过对镜片面形方程及球面度方程求解偏微分,构建了渐进多焦点镜片光焦度分布与面形误差的关系模型.根据国家标准规定的镜片有效区域实际屈光度与名义值差值小于0.1 D的要求,对加光度为2.0D(6.0D8.0D)的渐进面面形误差进行了实例分析.应用给定的面形误差结果进行实验加工的镜片,经分析后实验输出的光焦度变化符合所设定的国家标准要求的范围,进一步验证了面形误差与光焦度分布关系模型的正确性,为渐进多焦点镜片加工的面形控制精度提供理论依据.

Analysis of Relationship between Surface Error and Optical Power of PAL

The progressive addition lenses have been used widely applied, because its advantages can meet the requirements of distant and near vision at both time.The basic structure, design and evaluation method of progressive addition lenses are introduced in this paper.The relationship between surface error and optical power of progressive addition lenses is analyzed.The relationship equations are derived from the surface equation and sphere equation.Based on the national glasses fabrication standard that the difference between practical optical power and nominal designed value should be less than 0.1D during the lens effective area, A progressive addition lenses example with 2.0D addition (6.0D~8.0D) was designed, evaluated and surface error tolerance analyzed.After fabrication with given surface error, the optical power difference is calculated correspondingly.It is shown that the simulation result is consistent with the solution of relationship equations.The relationship model provides theoretical basis for the surface precision during lens fabrication process.