The oculomotor nerve is the third cranial nerve (CN III). It enables eye movements, such as focusing on an object that’s in motion. Cranial nerve III also makes it possible to move your eyes up, down and side to side.

Cranial nerve III works with other cranial nerves to control eye movements and support sensory functioning. It allows movement of the eye muscles, constriction of the pupil, focusing the eyes and the position of the upper eyelid.

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