标题： 进化与文石晶状体 显示英文标题

标题： Evolution and the Calcite Eye Lens

摘要： 文石是一种单轴双折射晶体，在其光学透明的形式中，已被用作动物晶状体，三叶虫就是其中一种动物。 由于文石的双折射效应，在使用文石作为透镜时存在困难。 当入射光的传播方向不完全与c轴重合时，图像会变得模糊。 本文评估了文石的模糊现象，并将晶状体眼透镜的非模糊特性与文石透镜进行了比较。 显示英文摘要

摘要： Calcite is a uniaxial, birefringent crystal, which in its optically transparent form, has been used for animal eye lenses, the trilobite being one such animal. Because of the calcite birefringence there is a difficulty in using calcite as a lens. When the propagation direction of incoming light is not exactly on the c-axis, the mages blur. In this paper, calcite blurring is evaluated, and the non-blurring by a crystallin eye lens is compared to a calcite one.