Lateral rectus

A muscle that plays a crucial role in the movement of the eye.

The lateral rectus is one of the six extraocular muscles responsible for controlling eye movements. Its primary role is to facilitate abduction of the eyeball, which means moving the eye away from the midline of the body. This muscle originates from the common tendinous ring located at the back of the orbit and inserts onto the outer surface of the eyeball.

Terminologia Anatomica

musculus rectus lateralis

System

Nervous system

Function

The primary function of the lateral rectus muscle is to allow the eye to rotate outward, enabling horizontal gaze to the side. This abduction is essential for various tasks, such as visually tracking moving objects and maintaining proper binocular vision, which is necessary for depth perception. When both lateral rectus muscles work in concert, they enable smooth and coordinated lateral movement of both eyes, minimizing the risk of double vision. Proper functioning of this muscle is critical in many activities, from reading to sports, where accurate eye tracking is essential.

Location

The lateral rectus is situated within the orbit, which is the bony cavity that houses the eyeball and its associated structures. It lies along the lateral aspect of the eyeball, specifically adjacent to the temporal area of the eye. The muscle arises from the common tendinous ring (annulus of Zinn) at the back of the orbit, positioned near the optic nerve, and travels laterally to insert at the sclera of the eyeball. Its specific positioning allows it to exert its force outward, making it highly efficient for its role in eye abduction.

Did You Know?

Dysfunction of the lateral rectus can lead to a condition known as strabismus, where the eyes do not properly align.
The lateral rectus is innervated by the abducens nerve (cranial nerve VI), which is solely responsible for lateral eye movement.
In some animals, the function of lateral rectus muscles is adapted for their specific visual requirements, such as in prey animals, which often have wider fields of vision.