Extraocular muscles

Extraocular muscles are the seven muscles that control the movement of the eye and one muscle that controls eyelid elevation. The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction.

Anatomy

There are seven extraocular muscles. They are classified into two groups: the four rectus muscles and the two oblique muscles. The superior oblique muscle and inferior oblique muscle control the torsional movement of the eye. The superior rectus muscle, inferior rectus muscle, lateral rectus muscle, and medial rectus muscle control the vertical and horizontal movements of the eye. The seventh muscle, the levator palpebrae superioris, elevates the eyelid.

Function

The extraocular muscles allow the eye to follow moving objects, maintain clear vision while the head is moving, and enable quick and voluntary eye movements, known as saccades. They also maintain the position of the eye in the orbit and control the reflexive movements of the eye.

Clinical significance

Dysfunction of the extraocular muscles can result in strabismus, a condition where the eyes do not properly align with each other when looking at an object. This can lead to diplopia (double vision), amblyopia (lazy eye), or astigmatism. Treatment options for strabismus include eye exercises, glasses, surgery, or a combination of these.

See also

• Eye movement
• Strabismus
• Diplopia
• Amblyopia
• Astigmatism

References

Extraocular muscles Resources
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