Luminance Profiles of Luminance Gradients Affect the Feeling of Dazzling

Abstract

The feeling of dazzling that is evoked by luminance gradients was examined. The stimulus consisted of a disk with uniform luminance surrounded by an annulus whose luminance was decreased from the inner boundary to the periphery. Three luminance profiles (linear, logistic, and inverse logistic) of a surrounding luminance ramp were used. The luminance of the disk and the maximum luminance of the annulus were also varied. The feeling of dazzling became stronger as the luminance of the disk and the maximum luminance of the annulus increased. The effect of the maximum luminance of the annulus was greater for the disk with low luminance than for that with high luminance. The feeling of dazzling tended to be greater for the logistic profile than for the other profiles. However, when the luminance of the disk and that at the inner boundary of the annulus were the same, the feeling of dazzling for the logistic profile was no stronger than that for the linear or the inverse-logistic profile. These results suggest that smooth transition from the disk to the annulus for the logistic profile suppresses the feeling of dazzling.