The dark central opening in the iris through which light enters the eye, its variable diameter being controlled by the dilator pupillae and sphincter pupillae muscles of the iris. See also accommodation reflex, Argyll Robertson pupil, dark adaptation, depth of field, glaucoma, light adaptation, oculomotor nerve, pupillary light reflex, sympathetic nervous system. pupillary adj. [From Latin pupilla a pupil, diminutive of pupa a girl or a doll, alluding to the tiny reflection in the eye]
Subjects: Psychology — Astronomy and Astrophysics.