Abstract:
Disability glare, which is the loss of visual performance due to scattered or reflected light, was measured using both letter acuity and contrast sensitivity tasks. Visual and performance measurements in the presence and absence of glare were obtained under conditions of simulated media opacification and induced defocus. Media opacification and defocus both affected contrast sensitivity and, for each condition, the reduction in visual performance was more marked at higher spatial frequencies. The addition of glare further reduced visual performance and this was measured more effectively by measurements of contrast sensitivity than by measurements of letter acuity.