Study on NCSFs of individual color mechanisms of human vision based on wave-front aberrations

Neural contrast sensitivity functions (NCSFs) of isolated color mechanisms are obtained based on the measurements of wave-front aberrations and isoluminant color contrast sensitivity functions (CSFs). Our study indicates that the mean NCSF and CSF of the red mechanism are higher than those of the green mechanism, respectively, while those of the blue mechanism are the lowest. However, the relative heights of the peak of NCSF and CSF between red and green mechanisms vary in subjects. There are some individuals whose peak values of NCSF and/or CSF of green mechanism are higher than that of the red mechanism. On the other hand, we find that the NCSFs and CSFs of isolated color mechanisms all exhibit the similar characteristics and variation tendency. With the statistical average, the NCSFs of the red, green and blue mechanisms are higher than the corresponding CSFs in the whole spatial frequency. The peaks of the NCSFs of isolated color mechanisms, comparing with the corresponding CSFs curves, shift toward higher spatial frequencies, especially for that of blue mechanism which has a largest shift of 3.9 c/deg.