Wavelength dependence of intraocular straylight

Wavelength dependence of retinal straylight has been a mystery since Stiles in 1929 [Stiles,W.S., 1929. The scattering theory of the effect of glare on the brightness difference threshold. Proc. R. Soc. Lond. (Biol.) 105, 131–41.] supposed it to have the strong Rayleigh type λ−4 dependence, typical for small particle light scattering, but which was never found. Using the accurate ‘compensation comparison’ approach, retinal straylight was measured from 625 to 457 nm. Subjects with a large variety of ocular pigmentation were included. Straylight was found to depend strongly on pigmentation of the eye, in addition to age. Young and well-pigmented eyes (young negroids) show nearly perfect λ−4 dependence. With less pigmentation (blue-eyed Caucasians), a red dominated component is added, negating the λ−4 dependence.