Pupillary abnormality

Abstract

upil size is determined by the interaction of the parasympathetic and the sympathetic nervous system, which constricts or dilates the iris. These are controlled by central nervous system inputs that are influenced by a variety of factors such as light, viewing distance, alertness and cognitive load. The pupil constricts in response to light (the direct light reflex) and, to a lesser extent, to near accommodation. The other pupil constricts consensually.