Abstract

Nine-week-old infants, color-normal adults, and red-green color-deficient adults were tested with an Anstis/Cavanagh OKN paradigm. 50 × 50°, 0.5-c/d, 50-townsend (TD) red-green (R/G), and yellow-black (Y/Bk) gratings were moved in opposite directions on a color video screen. An observer judged whether OKN occurred in the R/G or the Y/Bk direction (R/G OKN vs Y/Bk OKN). The R/G ratio was varied to find the OKN isoluminance point, and the Y/Bk contrast was varied to find the equivalent achromatic contrast. Extensive within-subject data were collected. In all cases, the direction of OKN was consistent and readily measured, and transitions from R/G to Y/Bk OKN were sharp. At Y/Bk contrast = 0, R/G OKN occurred in all subjects at all relative luminance values. For all groups of subjects, Y/Bk contrasts of ~15% allowed Y/Bk OKN to predominate over a confined range of R/G ratios. The isoluminance points differed systematically among groups; surprisingly, the equivalent achromatic contrasts (EACs) did not. Thus, at least in the present conditions, OKN isoluminance points are more useful than are EACs incharacteizing color vision deficiencies.

© 1988 Optical Society of America