Age-Related Effects of Glare on Luminance and Color Contrast Sensitivity

Abstract

To determine the effect of disability glare (DG) upon luminance and color contrast sensitivity for young and elderly subjects. DG was defined as the difference in contrast sensitivity with and without the presence of a glare source. Isoluminant color gratings were modulated either along a red-green (R-G) or blue-yellow (B-Y) axis. Without glare the effect of age on sensitivity to both luminance and R-G color-modulated gratings was small and did not reach statistical significance (P > 0.1). However, the reduction in sensitivity for B-Y color modulation was highly significant (P < 0.01). For both age groups, DG was greatest for the R-G stimulus and least for the B-Y. DG in the elderly increased relative to the young observers for both R-G and luminance-modulated gratings (P < 0.01) but not for B-Y (P > 0.01). The precise effect of a glare source on color discrimination depends upon a complex interaction between the chromaticity of the glare source and that of the stimulus. In certain circumstances, such as in our R-G stimulus, glare can dramatically reduce chromatic discrimination ability by desaturating the component colors.