The Stiles-Crawford effect of the first kind (SCE) is the phenomenon in which light entering
the eye near the center of the pupil appears brighter than light entering near the edge.
Previous investigations have found an increase in the directionality (steepness) of the effect
as the testing location moves from the center of the visual field to parafoveal positions, but
the effect of central field size has not been considered. The influence of field size on the SCE
was investigated using a uniaxial Maxwellian system in which stimulus presentation was …

The Stiles-Crawford effect (SCE) is the differential effectivity of light entering the eye at
different positions in the pupil. Its parameters are directionality (rate of change across the
pupil) and peak location in the pupil. Using a spatial light modulation system, I investigated
influences of field size, accommodation (focusing), and flicker frequency on the subjectively-
measured SCE. SCE directionality increased with increase in field size, while peak location
shifted temporally in the pupil with increase in focusing, but the SCE was not affected by a …