Contrast is enhanced by yellow lenses because of selective reduction of short-wavelength light

Purpose: Although many studies have shown a subjective preference for yello w lenses, there has been little success in determining the clinical nature of this benefit, Method: Contrast sensitivity, color vision, accommodative- convergence, and visual acuity were measured in a group of 20 young subject s along with subjective rating of their perception through clear control le nses (380-nm cut-off), yellow lenses (450-nm.cut-off), dark yellow lenses ( 511-nm cut-off), and orange lenses (527-nm cut-off). Results: A systematic detriment to color vision was found to occur with increasing cut-off wavele ngth of the yellow lenses (p < 0.001) and this was significantly correlated to subjective ratings of color (r = -0.66) and brightness (r = -0.34), Per ceived brightness significantly improved for the yellow (450-nm cut-off) le ns only (p < 0.001). Although tinted lenses reduced contrast sensitivity to a white on black grating, there was a significant improvement in low to mi drange spatial frequencies when measured using a white-on-blue grating, Con clusions: The detriment in color vision caused by yellow-colored lenses enh ances contrast when viewing bright objects against a blue-based background, such as the sky. Contrast of overlying objects is enhanced is due to the s elective reduction of short-wavelength light by the yellow lenses.