Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Medial rectus
Introduction
The medial rectus muscle is a muscle in the orbit.
As with most of the muscles of the orbit, it is innervated by the inferior division of the oculomotor nerve (Cranial Nerve III).
This muscle shares an origin with several other extrinsic eye muscles, the anulus tendineus, or common tendon.
It is the largest of the extraocular muscles and its only action is adduction of the eyeball.
Additional images
Additional images
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Horizontal section of the eyeball. -
Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure. -
