oculomotor nerve

oculomotor nerve The third cranial nerve. The oculomotor nerve is responsible for the nerve supply to muscles around the eye, including the upper eyelid muscle, which raises the eyelid; the extraocular muscle, which moves the eye inward; and the pupillary muscle, which constricts the pupil. Paralysis of the oculomotor nerve results in a drooping eyelid (ptosis), deviation of the eyeball outward (and therefore double vision), and a dilated (wide-open) pupil.