The effect of bleaching and backgrounds on pupil size

Measurements of pupil size and retinal rhodopsin in the dark after a full bleach confirm the suggestion of Alpern and Campbell that pupil dia. is linearly related to the fraction of unregenerated rhodopsin. This provides a transform [equation (1)] which can be used in conjunction with current ideas of visual adaptation to infer the pupil diameter at any luminance level (log I <= 5.0 scotopic td) in equilibrium viewing in a uniformly illuminated ganzfeld. Experimental determinations of such values on three normal subjects are in reasonable accord with expectation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34116/1/0000400.pd