Sclera

The Sclera is the white outer layer of the eye. It is a tough, fibrous tissue that extends from the cornea (the clear front section of the eye) to the optic nerve at the back of the eye. The sclera provides the eye with most of its structural strength.

Structure

The sclera is made up of several layers, including the episclera, the stroma, and the lamina fusca. The episclera is the outermost layer and contains blood vessels that nourish the sclera. The stroma is the middle, thickest layer and is made up of densely packed collagen fibers. The lamina fusca is the innermost layer and contains a large amount of pigment cells.

Function

The primary function of the sclera is to provide protection for the delicate structures inside the eye. It also serves as an attachment point for the extraocular muscles that control eye movement. In addition, the sclera helps to maintain the shape of the eye and provides resistance to internal and external forces that could cause damage.

Clinical significance

Diseases and conditions that can affect the sclera include scleritis, episcleritis, and scleral icterus. Scleritis and episcleritis are inflammatory conditions that can cause redness, pain, and vision problems. Scleral icterus is a condition in which the sclera becomes yellow due to an excess of bilirubin in the blood, often as a result of liver disease.

See also

• Cornea
• Extraocular muscles
• Optic nerve

External links

• American Academy of Ophthalmology - Sclera

Sclera

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  Sclera
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  Closeup of goat eye
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  A cow's eye
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  Western Lowland Gorilla