Roorda A, Williams D R
Center for Visual Science, University of Rochester, New York 14627, USA.
Nature. 1999 Feb 11;397(6719):520-2. doi: 10.1038/17383.
Human colour vision depends on three classes of receptor, the short- (S), medium- (M), and long- (L) wavelength-sensitive cones. These cone classes are interleaved in a single mosaic so that, at each point in the retina, only a single class of cone samples the retinal image. As a consequence, observers with normal trichromatic colour vision are necessarily colour blind on a local spatial scale. The limits this places on vision depend on the relative numbers and arrangement of cones. Although the topography of human S cones is known, the human L- and M-cone submosaics have resisted analysis. Adaptive optics, a technique used to overcome blur in ground-based telescopes, can also overcome blur in the eye, allowing the sharpest images ever taken of the living retina. Here we combine adaptive optics and retinal densitometry to obtain what are, to our knowledge, the first images of the arrangement of S, M and L cones in the living human eye. The proportion of L to M cones is strikingly different in two male subjects, each of whom has normal colour vision. The mosaics of both subjects have large patches in which either M or L cones are missing. This arrangement reduces the eye's ability to recover colour variations of high spatial frequency in the environment but may improve the recovery of luminance variations of high spatial frequency.
人类的色觉依赖于三类感受器，即对短波长（S）、中波长（M）和长波长（L）敏感的视锥细胞。这些视锥细胞类别交织在一个单一的镶嵌结构中，使得在视网膜的每个点上，只有一类视锥细胞对视网膜图像进行采样。因此，具有正常三色视觉的观察者在局部空间尺度上必然是色盲的。这对视觉造成的限制取决于视锥细胞的相对数量和排列方式。尽管人类S视锥细胞的地形图是已知的，但人类L视锥细胞和M视锥细胞的亚镶嵌结构一直难以分析。自适应光学技术，一种用于克服地面望远镜模糊的技术，也可以克服眼睛中的模糊，从而获得有史以来对活体视网膜拍摄的最清晰图像。在这里，我们结合自适应光学和视网膜密度测量法，获得了据我们所知的活体人眼中S、M和L视锥细胞排列的首批图像。在两名色觉正常的男性受试者中，L视锥细胞与M视锥细胞的比例显著不同。两名受试者的镶嵌结构都有大片区域缺失M视锥细胞或L视锥细胞。这种排列降低了眼睛恢复环境中高空间频率颜色变化的能力，但可能会提高对高空间频率亮度变化的恢复能力。
