Pupil size and microgravity: A study in parabolic flight

Abstract

A relative afferent pupillary defect usually occurs in an eye with unilateral or asymmetric optic nerve or extensive retinal disease. In general, the eye with poorer visual acuity has the afferent pupillary defect. Twenty-five patients are reported, however, in whom an afferent pupillary defect occurred in the eye with better visual acuity. These eyes had optic nerve or retinal dysfunction. The eyes with worse visual acuity but no afferent pupillary defect had an abnormality of the ocular media (corneal opacity, hyphema, anterior segment membrane, cataract, or vitreous opacity), amblyopia, refractive error, age-related macular degeneration, or cystoid macular edema. An afferent pupillary defect does not necessarily occur in the eye with poorer visual acuity.