Hammer R M, Holden B A
Cornea and Contact Lens Research Unit, School of Optometry, University of New South Wales, Sydney, Australia.
Optom Vis Sci. 1994 Aug;71(8):522-8. doi: 10.1097/00006324-199408000-00006.
It is important to assess aspheric rigid contact lenses not only for fit, but also for optical performance. Using ray tracing techniques, on-eye total longitudinal aberration induced by aspheric contact lenses and the variation of the tangential focus with ray height were determined. Both the contact lens and tear lens were taken into account. The front and back surface profiles of the contact lens and the corneal profile were modeled as conic sections. On-eye aberration was found to become strongly more positive as the p-value of the contact lens front surface increased. It became more negative as the back surface p-value increased, but the tendency was weaker. These calculations indicate that selection of a contact lens back surface p-value according to fitting considerations without choosing a front surface p-value to minimize aberrations could, in some circumstances, lead to a reduction in visual performance.
评估非球面硬性接触镜时，不仅要评估其适配性，还要评估其光学性能，这很重要。使用光线追迹技术，确定了非球面接触镜引起的眼上总纵向像差以及切向焦点随光线高度的变化。同时考虑了接触镜和泪液透镜。将接触镜的前表面和后表面轮廓以及角膜轮廓建模为圆锥曲线。研究发现，随着接触镜前表面的p值增加，眼上像差会变得更强烈地正向增加。随着后表面p值增加，像差会变得更负向，但趋势较弱。这些计算表明，在某些情况下，根据适配考虑选择接触镜后表面p值而不选择前表面p值以最小化像差，可能会导致视觉性能下降。
