ANATOMY

Detailed explanation-1: -The trochlear nerve is one of 12 sets of cranial nerves. It enables movement in the eye’s superior oblique muscle . This makes it possible to look down. The nerve also enables you to move your eyes toward your nose or away from it.

Detailed explanation-2: -Some cranial nerves also contribute to voluntary and involuntary muscle movements. The trochlear nerve, also known as cranial nerve 4 (CN IV), controls the superior oblique muscle in your eye. This muscle allows you to move your eyeball down and shift your gaze from side to side.

Detailed explanation-3: -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.

Detailed explanation-4: -Inferior rectus muscle (moves the eye down) Superior rectus muscle (moves the eye up) Inferior oblique muscle (moves the eye up and out)

Detailed explanation-5: -Fourth nerve palsy generally affects only one eye, but it can affect both eyes as well. The most common symptoms of fourth nerve palsy include: Double vision (diplopia) when both eyes are open. Strabismus, or an eye turn that causes the affected eye to turn upward.