Table of ContentsView AllTable of ContentsAnatomyFunctionAssociated ConditionsTests
Table of ContentsView All
View All
Table of Contents
Anatomy
Function
Associated Conditions
Tests
The cornea is the clear dome of tissue at the front of the eye. It connects smoothly to thesclera(the white part of the eye). The cornea refracts light through thelensbelow it, which allows the eye to process images. Injuries to the cornea can impair a person’s vision.
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In most people, the cornea is somewhat oval in shape, and it is thicker at the edges than it is at the center. The cornea sits above theirisand the lens.
Structure
Although it is very thin and transparent, the cornea is made up of five separate tissue layers.
Anatomical Variations
Congenital (present at birth) abnormalities of the cornea do occur, and they usually cause the cornea to be cloudy instead of clear. When these abnormalities occur, they often appear in conjunction with other medical conditions, including:
The cornea’s convex (domed) shape serves to refract (bend) light before it passes through the iris and the lens. The lens further refracts the light to refine the image projected onto theretina(the tissue that lines the back of the inner eyeball).
The degree of curvature of the cornea greatly affects its ability to refract light. Abnormalities of corneal curvature, such as keratoconus (a cone-shaped cornea), can make image processing poor or even impossible.
Because of its prominence at the front of the eye, the cornea is subject to the risk of abrasion (scratching, scraping). Minor abrasions that affect only the epithelial layer usually heal themselves within 24 hours. However, deeper scratches that reach Bowman’s layer often produce corneal scarring that can impair vision. Injuries that extend below Bowman’s layer, such as a penetrating eye wound, can cause blindness.
SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Academy of Ophthalmology.Corneal anatomy, symptoms, and examination.Georgia State University.Refraction and the eye.Katzman LR, Reiser BJ.Pediatric corneal opacities. American Academy of Ophthalmology. Updated June 21, 2016.Sridhar MS.Anatomy of cornea and ocular surface. Indian J Ophthalmol. 2018 Feb;66(2):190-194.U.S. National Eye Institute.Corneal conditions. Updated August 3, 2019.U.S. National Library of Medicine, MedlinePlus.Corneal disorders. Updated January 8, 2020.U.S. National Library of Medicine, MedlinePlus.Fluorescein eye stain. Updated March 4, 2020.U.S. National Library of Medicine, MedlinePlus.Cornea. Updated August 28, 2018.
Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Academy of Ophthalmology.Corneal anatomy, symptoms, and examination.Georgia State University.Refraction and the eye.Katzman LR, Reiser BJ.Pediatric corneal opacities. American Academy of Ophthalmology. Updated June 21, 2016.Sridhar MS.Anatomy of cornea and ocular surface. Indian J Ophthalmol. 2018 Feb;66(2):190-194.U.S. National Eye Institute.Corneal conditions. Updated August 3, 2019.U.S. National Library of Medicine, MedlinePlus.Corneal disorders. Updated January 8, 2020.U.S. National Library of Medicine, MedlinePlus.Fluorescein eye stain. Updated March 4, 2020.U.S. National Library of Medicine, MedlinePlus.Cornea. Updated August 28, 2018.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American Academy of Ophthalmology.Corneal anatomy, symptoms, and examination.Georgia State University.Refraction and the eye.Katzman LR, Reiser BJ.Pediatric corneal opacities. American Academy of Ophthalmology. Updated June 21, 2016.Sridhar MS.Anatomy of cornea and ocular surface. Indian J Ophthalmol. 2018 Feb;66(2):190-194.U.S. National Eye Institute.Corneal conditions. Updated August 3, 2019.U.S. National Library of Medicine, MedlinePlus.Corneal disorders. Updated January 8, 2020.U.S. National Library of Medicine, MedlinePlus.Fluorescein eye stain. Updated March 4, 2020.U.S. National Library of Medicine, MedlinePlus.Cornea. Updated August 28, 2018.
American Academy of Ophthalmology.Corneal anatomy, symptoms, and examination.
Georgia State University.Refraction and the eye.
Katzman LR, Reiser BJ.Pediatric corneal opacities. American Academy of Ophthalmology. Updated June 21, 2016.
Sridhar MS.Anatomy of cornea and ocular surface. Indian J Ophthalmol. 2018 Feb;66(2):190-194.
U.S. National Eye Institute.Corneal conditions. Updated August 3, 2019.
U.S. National Library of Medicine, MedlinePlus.Corneal disorders. Updated January 8, 2020.
U.S. National Library of Medicine, MedlinePlus.Fluorescein eye stain. Updated March 4, 2020.
U.S. National Library of Medicine, MedlinePlus.Cornea. Updated August 28, 2018.
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