Pupillary constriction in the EYE in response to light. The direct light reflex involves pupillary constriction in the eye into which a light is shone; the consensual light reflex is the pupillary constriction that occurs in the other eye. The afferent, or incoming, pathway of the reflex is via the optic nerve, and the efferent, or outward, pathway is via the oculomotor nerve.