Definition: The cornea is the clear covering of the eye, which consists of five layers. It protects the eye and acts as a lens. Imperfections in the shape of the cornea can create the need for glasses. The cornea also acts as a filter for UV light rays.
A cornea that is too curved leads to myopia, not enough curve causes hyperopia, and irregular curves cause astigmatism.
The layers of the cornea are as follows from outside to inside:
- The Epithelium: The layer that prevents foreign material such as dirt from getting into the eye.
- Bowman's Layer: Made of collagen, this layer is very strong and subject to scarring.
- Stroma: The thickest layer, made up of water and collagen, responsible for conducting light through the cornea.
- Descemet's Membrane: A layer that regenerates easily and protects the eye from infection.
- The Endothelium: The thinnest layer of the cornea, responsible for moving fluid away from the cornea, which keeps the tissue transparent.
The cornea has no blood supply, it is supplied with nutrients by the fluid contained in the eye, the vitreous humor.
Also Known As: corneal,
Alternate Spellings: cornea, corneas,
Examples:
The patient had to wear an eye patch because of a corneal abrasion, luckily, the cornea heals quickly.
