ON THE STILES-CRAWFORD EFFECT WITH AGE

Purpose. To determine whether the Stiles-Crawford effect remains stabl e after subjects have aged 30 years. Methods. The relative luminous ef ficiency as a function of pupil position (Stiles-Crawford effect) was determined for the same seven subjects on the same apparatus in the 19 60s and in 1995. The pupil opening was traversed nine times, at 20 deg rees azimuth intervals. Data were fit with a revolution paraboloid yie lding a peak position (x(0), y(0)) and a peakedness (rho). Results. Tw o of seven subjects showed a significant, but small, decrease in rho, and the other five showed no change. No clear outcome in x(0), y(0) ch anges could be reported because of differences in pupil dilation then and now. Conclusions. Although exceptions are found on the stability o f the Stiles-Crawford effect with age, the authors can still conclude that it is stable.