Encyclopedia > Iris of the eye

  Article Content

Iris (anatomy)

Redirected from Iris of the eye

Iris, in anatomy, is the sphincter around the pupil of the eye, permitting the pupil to open and close to control the amount of light striking the retina. The iris is brightly pigmented, with colours ranging from grey to green, blue, brown, and nearly purple or black.

A person's "eye colour" is actually the colour of their iris (except, of course, that a black eye is a bruise[?] of the skin around the eye, and pink eye is a kind of infection). Certain eye colours are sometimes seen as being especially attractive, and cosmetic contact lenses can be worn to mask one's natural eye colour with another.

When photographed with a flash, the iris cannot close fast enough, resulting in the red eye effect.

Scanning the iris is a biometric[?] method used for the recognition of human individuals.



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Encyclopedia of Marxism

... is an online encyclopedia about Marxism, part of the GFDLed Marxist Internet Archive[?]. Primary contributors include Brian Basgen, Andy Blunden, Sally Ryan, and David ...