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. 光度視網(wǎng)膜亮度單位,相當于每平方米有一燭光亮度的表面,通過(guò)一平方毫米的瞳孔區域,到達視網(wǎng)膜的光線(xiàn)數量