Enoch J M
Doc Ophthalmol. 1980 Apr 15;48(2):373-88. doi: 10.1007/BF00141466.
Vertebrate photoreceptors act as optical waveguides. They exhibit directionality, non-uniform distribution of energy within and immediately about the receptor, etc. Photolabile pigment absorption favors light traveling axially down the receptor. Clearly these properties influence response of the transducer. Retinal receptors, rods and cones, are aligned normally with a point approximating the center of the exit pupil of the eye. Taken together, these findings suggest that a prime role of receptor optics is to favor acceptance of the pertinent visual stimulus passing through the pupillary aperture and to inhibit stray light noise contained in the integrating sphere-like eyes. Many intriguing problems remain to be resolved. It is necessary to relate the properties of the receptor as a waveguide to determinations of directional sensitivity of the retina (Stiles-Crawford effects), and in particular, to understand mechanisms leading to fine receptor alignment. There must also be a pathology of receptor orientation--a science still in its infancy.
脊椎动物的光感受器起着光波导的作用。它们表现出方向性、感受器内部及紧邻感受器处能量的非均匀分布等。光不稳定色素的吸收有利于光线沿感受器轴向传播。显然，这些特性会影响换能器的响应。视网膜感受器，即视杆细胞和视锥细胞，通常与近似眼睛出瞳中心的一点对齐。综合这些发现表明，感受器光学的一个主要作用是有利于接受穿过瞳孔孔径的相关视觉刺激，并抑制类似积分球的眼睛中包含的杂散光噪声。许多有趣的问题仍有待解决。有必要将感受器作为波导的特性与视网膜方向敏感性的测定（斯泰尔斯 - 克劳福德效应）联系起来，特别是要理解导致感受器精确对齐的机制。还必须存在感受器定向病理学——这门科学仍处于起步阶段。
