1. 光度視網膜亮度單位，相當于每平方米有一燭光亮度的表面，通過一平方毫米的瞳孔區(qū)域，到達視網膜的光線數(shù)量
   A unit of retinal illumination, equal to the amount of light that reaches the retina through 1 square millimeter of pupil area from a surface having a brightness of 1 candela per square meter.
2. 屈光正常當平行光線恰好聚焦于視網膜并形成清晰視覺時正常眼睛的狀態(tài)
   The condition of the normal eye when parallel rays are focused exactly on the retina and vision is perfect.

視的英語翻譯：

網膜的英語翻譯：