SIZE-DISTANCE VARIANCE AND EYE ACCOMMODATION - THE WAYS OF AN INVESTIGATOR

Biased judgments of size and distance are encountered with all types o f imaging displays, and the literature on visual perception is replete with violations of the size-distance invariance hypothesis, including the paradoxical moon illusion. To sort out the basic variables that r elate these seemingly unrelated events calls for unfettered multifacto r experimentation rather than the severe reduction of traditional psyc hophysical methodology. The high correlation among the focal distance of the eyes, apparent size, and changes in the locus of the retinal bl ind spot would never have been discovered if all cues to distance othe r than accommodation had been eliminated, as called for by experimenta l reductionists.