trochlear nerve

The trochlear nerve, also known as cranial nerve IV, is a small nerve responsible for controlling one of the muscles that move the eye. Specifically, it helps rotate the eye downward and outward, allowing you to look down and to the side. Originating from the brainstem, it travels to the eye socket to connect with its muscle. Damage to this nerve can cause double vision or difficulty moving the eye properly, often leading to vertical or tilting eye misalignment. Despite its small size, the trochlear nerve plays a crucial role in eye movement and coordination.