Bone Richard A, Draper Grenville
Department of Physics, Florida International University, 11200 SW 8th Street, Miami, Florida 33199, USA.
Appl Opt. 2007 Dec 1;46(34):8351-7. doi: 10.1364/ao.46.008351.
We have investigated the optical anisotropy of the human cornea using a polarizing microscope normally used for optical mineralogy studies. The central part of the cornea was removed from 14 eyes (seven donors). With the sample placed on the microscope stage, we consistently observed hyperbolic isogyres characteristic of a negative biaxial material. The angle between the optic axes, generally similar in both eyes, ranged from 12 degrees to 40 degrees (mean+/-SD=31 degrees +/-8 degrees ). The optic axial plane always inclined downward in the nasal direction at 1 degrees -45 degrees below the horizontal (mean+/-SD=22+/-13 degrees ). The retardance produced by the corneas was estimated to be less than 200 nm. In conclusion, the human cornea possesses the anisotropy of a negative biaxial material. Both the angle between the optic axes and the retardance were fairly constant among the majority of samples, suggestive of uniformity in corneal structure.
我们使用通常用于光学矿物学研究的偏光显微镜研究了人角膜的光学各向异性。从14只眼睛（7位供体）中取出角膜的中央部分。将样品置于显微镜载物台上时，我们始终观察到负双轴材料特有的双曲线等色线。光轴之间的角度在两只眼睛中通常相似，范围为12度至40度（平均值±标准差=31度±8度）。光轴平面总是在鼻侧方向向下倾斜，低于水平方向1度至45度（平均值±标准差=22±13度）。角膜产生的延迟估计小于200纳米。总之，人角膜具有负双轴材料的各向异性。大多数样品中光轴之间的角度和延迟都相当恒定，表明角膜结构具有均匀性。
