The superior oblique is a muscle located in the eye that plays a crucial role in controlling eye movement. It is responsible for rotating the eye downward and outward, allowing for better focus on objects that are below and to the side. This muscle is innervated by the trochlear nerve, which is the fourth cranial nerve. When the superior oblique is functioning properly, it helps maintain proper alignment of the eyes, contributing to clear and coordinated vision. Dysfunction or weakness in this muscle can lead to conditions such as diplopia, or double vision, affecting a person's ability to see clearly.