渐进多焦点镜片的逐点定向曲率补偿优化设计

提出一种利用逐点定向曲率补偿法对渐进多焦点镜片初始模型进行整体优化以减小周边散光区（俗称盲区）的优化设计方法。推导出自由曲面任意方向法曲率的计算公式、确定主曲率和主方向的方法，求出镜片初始模型上各点的曲率差和最大曲率方向、最小曲率方向，通过迭加由不同曲率、不同轴向微小柱面构成的自由曲面，来实现逐点定向曲率补偿，使镜片各点的曲率差适当减小，从而减小散光。给出具体优化步骤和一个优化设计实例，并进行实际加工制作与检测。对比优化前后的光焦度和散光度的面形分布图。结果表明，逐点定向曲率补偿法能有效减小渐进多焦点镜片初始模型的最大散光并明显扩大视远区清晰视觉范围。

Optimization Design for Progressive Addition Lenses by Pointwise Directional Curvature Compensation

A global optimizing method using pointwise directional curvature compensation which can reduce the undesirable astigmatism is proposed. The calculation formula of normal curvature at arbitrary direction is deducted and the method is proposed to determine the principal curvature and principal direction. The principal curvature difference and the directions of the maximum and minimum curvature of the initial progressive addition lens are calculated. The optimizaiton method can reduce the astigmatism by adding the freeform surface consisting of micro cylinders with different curvatures and different directions. The optimization algorithm and an example are given. An initial progressive addition lens and an optimized lens by this method are manufactured and tested. Compared with the initial lens, the optimized lens has smaller maximum astigmatism value and larger clear region in the distance-vision zone.