Abstract
This laboratory study evaluated the effect of the size of the glare source on discomfort glare. The subjects performed two simultaneous tasks: continuous compensatory tracking and evaluation of discomfort from glare stimuli presented periodically in the near visual periphery. The results indicate that there was a small but statistically significant effect of glare size, with the smaller glare stimuli resulting in more discomfort glare. The mean difference over the range of glare illuminances tested was 0.2 points on the 9- point response scale.