The medial rectus muscle
Inserted into the anterior, medial surface of the eyes with a 5.5 mm distance from the limbus, the medial rectus muscle has the shortest tendons among all rectus muscles. It is innervated by Cranial Nerve III and has no significant contribution to other ocular eye movements except to draw the pupil closer to the midline. Even so, the medial rectus muscle plays an indispensable role in ocular convergence, and it is essential to near-field focus, such as when reading books. [5]
