Abstract

Vos, Walraven, and van Meeteren (1976) have proposed an empirical scattering factor for the ocular media (LSF) in terms of the illuminance on the eye from a glare source (E), an equivalent veiling luminance (L_eq), and the glare angle (GA). Rearranging their equation (3) gives the following expression: Paulsson and Sjöstrand (1980) have suggested that measurements of LSF may be developed into a useful clinical index of light scatter in the ocular media by deriving an expression for LSF in terms of the contrast threshold without a glare source (M₁), threshold with a glare source (M₂), mean luminance of the contrast target (L), and glare illuminance (E, same as above): This calculation is intended to be unaffected by reasonable variations in L and E, because of compensating changes in contrast thresholds. Thus, it should represent an intrinsic scattering property of the ocular media. They state that this expression is valid "if we assume that psychophysical effects such as adaptation and pupil size can be neglected" (page 403).

© 1991 Optical Society of America