Effect of filters on disability glare.
Disability glare is the reduction in visual performance caused by a peripheral glare source. We examined the effect of a long wavelength pass (red) and a short wavelength pass (blue) filter on disability glare in the presence of varying amounts of induced wavelength dependent stray light. Measurements were made in the absence of any filter and then repeated in the presence of the red and blue filters whose luminous transmission factors were equal relative to both the stimulus and the glare source. Neither of the filters had any effect on disability glare. Filters not only reduce the amount of veiling luminance from the glare source, but also reduce the ability to detect the stimulus. Disability glare was not significantly different with the red and blue filters, even in the presence of wavelength dependent scatter. Calculation of the veiling luminance transmitted by each filter revealed that the difference in veiling luminance in the two filter conditions was insufficient to result in a measurable difference in disability glare.
Steen
R
R
Department of Vision Sciences, University of Aston, Birmingham, UK.
Whitaker
D
D
Elliott
D B
DB
Wild
J M
JM
D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology; D012542:Scattering, Radiation; D013053:Spectrophotometry; D014786:Vision Disorders / Q000517:prevention & control*