研究内渐进多焦点镜片的前表面光焦度对该镜片的光焦度和散光的影响。设计出远用光焦度为2~10m-1, 附加光焦度为2m-1的渐进表面数据, 分别与1~10m-1的前表面光焦度匹配后输入Rotlex自由曲面检测仪转化为理论光焦度和散光度并进行统计分析。结果表明: 在内渐进多焦点镜片的前表面光焦度匹配图中, 存在扁椭圆区域, 在该区域内匹配的内渐进多焦点镜片的远用区和近用区视觉清晰范围最大, 且最大散光不大于附加光焦度。对于远用光焦度为非负的内渐进多焦点镜片, 子午线上光焦度会随着前表面光焦度的增大而偏大。远用区为较大的正光焦度时, 远用区和近用区清晰视觉范围明显较小。

The effect of the front surface power of progressive addition lenses (PALs) on power and astigmatism is studied. The sag data of the PALs with 2~10m-1 distance power and 2m-1 addition power is designed. The PALs data and 1~10m-1 front sphere surface power parameters are imported into Rotlex Free Form Verifier (FFV) to translate the topography into theoretical power and astigmatism and then to pursue statistical analysis. It is shown that, in the graph of matching front sphere surface power and PALs, there is an elliptical region in which not only the clear visual areas in distance and near zone are maximum but also the maximum astigmatism on the PALs are not more than the addition power. For the PALs with positive (or zero) distance power, the power on the meridian line increases as the increasing of the front surface power. The clear visual areas in the distance and near zone are obviously small on the PALs with big positive distance power.