Editing Cornea (section)

{{Short description|Transparent front layer of the eye}}
{{Other uses}}
{{Infobox anatomy
| Name      = Cornea
| Latin       = cornea
| part_of = Front of [[eye]]
| system = [[Visual system]]
| Function    = [[Refract]] light
| Image       = Cornea.png
| Caption     = Schematic diagram of the right [[human eye]] showing the cornea as separated from the [[sclera]] by the [[corneal limbus]]
| System      =
| Precursor   =
}}

The '''cornea''' is the [[transparency (optics)|transparent]] front part of the [[eyeball]] which covers the [[Iris (anatomy)|iris]], [[pupil]], and [[Anterior chamber of eyeball|anterior chamber]]. Along with the anterior chamber and [[Lens (anatomy)|lens]], the cornea [[Refraction|refracts]] light, accounting for approximately two-thirds of the eye's total [[optical power]].<ref name="Cassin">{{cite book |last1=Cassin |first1=B. |last2=Solomon |first2=S. |title=Dictionary of Eye Terminology |location=Gainesville, Florida |publisher=Triad Publishing Company |year=1990}}{{page needed|date=September 2012}}</ref><ref name="Goldstein">{{cite book |last1=Goldstein |first1=E. Bruce |title=Sensation & Perception |edition=7th |location=Canada |publisher=Thompson Wadsworth |year=2007|isbn=9780534558109}}{{page needed|date=September 2012}}</ref> In humans, the refractive power of the cornea is approximately 43 [[dioptre]]s.<ref>{{cite web |last=Najjar |first=Dany |url=http://www.eyeweb.org/optics.htm |title=Clinical optics and refraction |url-status=dead |archive-url=https://archive.today/20120529165007/http://www.eyeweb.org/optics.htm |archive-date=2012-05-29 }}{{MEDRS|date=September 2012}}</ref> The cornea can be reshaped by surgical procedures such as [[LASIK]].<ref name="Finn">{{cite news|url=https://www.washingtonpost.com/national/health-science/medical-mystery-preparation-for-surgery-revealed-cause-of-deteriorating-eyesight/2011/11/26/gIQAwVLj4O_story.html|title=Medical Mystery: Preparation for surgery revealed cause of deteriorating eyesight|last=Finn|first=Peter|date=20 December 2012|newspaper=The Washington Post}}</ref>

While the cornea contributes most of the eye's focusing power, its [[Focus (optics)|focus]] is fixed. [[Accommodation (eye)|Accommodation]] (the refocusing of light to better view near objects) is accomplished by changing the geometry of the lens.  Medical terms related to the cornea often start with the prefix "''[[wikt:kerat-|kerat-]]''" from the [[Ancient Greek|Greek]] word κέρας, ''horn''.