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.

The vagus nerve is one of 12 cranial nerves in the body. It’s responsible for various bodily functions, including digestion, heart rate, and breathing. There are 12 cranial nerves in the body. They ...