Vorobyev Misha
Vision, Touch and Hearing Research Centre, University of Queensland, Brisbane, QLD 4072, Australia.
Proc Biol Sci. 2003 Jun 22;270(1521):1255-61. doi: 10.1098/rspb.2003.2381.
The eyes of most diurnal reptiles and birds contain coloured retinal filters-oil droplets. Although these filters are widespread, their adaptive advantage remains uncertain. To understand why coloured oil droplets appeared and were retained during evolution, I consider both the benefits and the costs of light filtering in the retina. Oil droplets decrease cone quantum catch and reduce the overlap in sensitivity between spectrally adjacent cones. The reduction of spectral overlap increases the volume occupied by object colours in a cone space, whereas the decrease in quantum catch increases noise, and thus reduces the discriminability of similar colours. The trade-off between these two effects determines the total benefit of oil droplets. Calculations show that coloured oil droplets increase the number of object colours that can be discriminated, and thus are beneficial for colour vision.
大多数昼行性爬行动物和鸟类的眼睛含有带颜色的视网膜滤光器——油滴。尽管这些滤光器很常见，但其适应性优势仍不明确。为了理解为什么彩色油滴在进化过程中出现并保留下来，我考虑了视网膜中光过滤的益处和成本。油滴会减少视锥细胞的量子捕获，并减少光谱相邻视锥细胞之间的敏感度重叠。光谱重叠的减少增加了物体颜色在视锥细胞空间中所占的体积，而量子捕获的减少会增加噪声，从而降低相似颜色的可辨别性。这两种效应之间的权衡决定了油滴的总体益处。计算表明，彩色油滴增加了可辨别的物体颜色数量，因此有利于色觉。
