Every human eye has 6 eye muscles. This includes the lateral rectus, the medial rectus, the inferior rectus, the superior rectus, the inferior oblique, and the superior oblique. In this post, we’ll talk about the first three muscles listed and discover their function and purpose in the human eye.
The Lateral Rectus is a muscle of the eye’s orbit. The main function of this muscle is to pull the pupil away from the midline of the body. The word Lateral Rectus comes from the Latin latus, meaning “side” and rectus, “straight.” Here is more in-depth information on the lateral rectus muscle:
“The lateral rectus originates at the lateral part of the annulus of Zinn, also known as the annular tendon or common tendinous ring, and inserts into the temporal side of the eyeball. The annulus of Zinn is a tendinous ring that surrounds the optic nerve and serves as the origin for four of the six extraocular muscles, excluding the inferior oblique muscle and superior oblique muscle.” (We got that quote straight from Wikipedia.)
The Medial Rectus is also a muscle of the eye’s orbit. The only function of the Medial Rectus is to bring the pupil closer to the midline of the body. The word Medial Rectus comes from the Latin medius, “middle.” Discover more about the medial rectus here:
“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.” (Wikipedia)
The Inferior Rectus is also a muscle of the orbit. This muscle has multiple functions, mainly helping to extort the eye. Here are more details of the inferior rectus muscle:
“[The inferior rectus muscle] depresses, adducts, and helps extort (rotate laterally) the eye. The inferior rectus muscle is the only muscle that is capable of depressing the pupil when it is in a fully abducted position.” (Wikipedia)
What do you know about the muscles of the eye? Comment any questions you have about the eye’s muscles and we’ll answer them!