Thibos L N, Bradley A, Still D L, Zhang X, Howarth P A
Department of Visual Sciences, School of Optometry, Indiana University, Bloomington 47405.
Vision Res. 1990;30(1):33-49. doi: 10.1016/0042-6989(90)90126-6.
We have determined the transverse chromatic aberration of the human eye by measuring the apparent offset of a two-color vernier viewed foveally through a displaced, pinhole aperture. For the same subjects, we also determined the longitudinal chromatic aberration for foveal viewing by the method of best focus. In both cases, the results were closely predicted by a simple, reduced-eye optical-model for which transverse and longitudinal chromatic aberration are directly proportional, with the constant of proportionally being the amount of displacement of the pinhole from the visual axis. Further measurements revealed that the natural pupil was closely centered on the visual axis for two subjects and slightly displaced in the temporal direction for three other subjects. One implication of these results is that, although the eye has substantial chromatic aberration, the pupil is positioned so as to minimize the transverse component of the aberration for central vision, thereby optimizing foveal image quality for polychromatic objects.
我们通过测量经移位针孔光阑中央凹注视的双色游标视在偏移，测定了人眼的横向色差。对于相同的受试者，我们还采用最佳聚焦法测定了中央凹注视的纵向色差。在这两种情况下，结果都能由一个简单的简约眼光学模型精确预测，该模型中横向色差和纵向色差成正比，比例常数为针孔相对于视轴的位移量。进一步测量发现，两名受试者的自然瞳孔紧密位于视轴中心，另外三名受试者的瞳孔则向颞侧稍有偏移。这些结果的一个启示是，尽管眼睛存在显著的色差，但瞳孔的位置可将中央视觉色差的横向分量降至最低，从而优化多色物体的中央凹图像质量。
