Influence of ocular light scatter on the eye's optical performance.

Psychophysical experiments, with a new paradigm but in broad conformity with classical results on glare, were used to estimate the scattering in the eye. Combining the data with those from a companion experiment [J. Opt. Soc. Am. A 12, 1411-1416 (1995)] using objective double-pass measurements of the retinal image in the same subjects permitted a synthesis of the complete point-spread function. Results were obtained on two young subjects and one older one with more prominent scatter but normal visual acuity. This permitted the derivation of performance parameters of the eyes, such as the Strehl ratio and cumulative light functions. When the scattering was more prominent, we were able to characterize performance losses that manifested themselves in changes in absolute and contrast detection thresholds.