The optical sensitivity for the cones of the human eye and the horse eye at intensities corresponding to moonlight.

A[18]B[19] An average of the cone diameter in parafovea and perifovea is used.C[20]DThe tapetum is the reason for the double effective length of the cone outer segments.A[18]、B[19]：采用黄斑旁区（parafovea）与黄斑周区（perifovea）的视锥细胞直径（cone diameter）的平均值。C[20]、D：反光膜（tapetum）是导致视锥细胞外节（cone outer segments）有效长度翻倍的原因。