A complex system of nerves and muscles enables the human eye to blink, gaze, and shift focus. The trochlear nerve is one of six cranial nerves that carry electrical impulses from the brain to the eye.

Your eye is made up of three nerves that control the movement of your eyes, the location of your eyelids, and the size of your pupils. These nerves are the oculomotor nerve, the trochlear nerve, and ...