NEET PG DENTAL EXAM

Detailed explanation-1: -The iris sphincter is innervated by the parasympathetic nervous system, the part of the autonomic nervous system that is involved in homeostasis (i.e. keeping the body in stable condition); the link between pupil constriction and the parasympathetic nervous explains why pupils are relatively small at rest.

Detailed explanation-2: -Constriction of the pupils is mediated by the parasympathetic nervous system, whereas dilation of the pupils is mediated by the sympathetic nervous system. Pupillary constriction to light occurs via an involuntary reflex arc.