Paradoxical pupil in congenital achromatopsia

Children with congenital achromatopsia possess an interesting paradoxical pupillary constriction to darkness that has not been previously described. This paper describes three children in whom this paradoxical pupillary reaction was documented with infrared pupillometry. The literature on the pupil in achromatopsia is reviewed and a tentative testable model of the reaction is hypothesized.This work was supported in part by Public Health Service Institutional National Research Study Award # EY 07021 from the National Institutes of Health, Bethesda, Maryland and National Institutes of Health Research Grant 1236-03-04.