What is Iris (eye)?
{{about|the Iris of the eye|other uses|Iris}} {{Infobox anatomy | Name = Iris | Latin = iris | Image = Human eye close up, anterior view.jpg | Caption = '''Iris''' in humans, is the colored (typically blue or brown) area, with the [[pupil]] (the circular black spot) in its center, and surrounded by the white [[sclera]]. Overlying [[cornea]] is completely transparent so is not visible, except the high-gloss luster it gives the eye. Also pictured are the red blood vessels within the sclera. These structures are easily visible on any person's eyes. | Width = | Image2 = Schematic diagram of the human eye en.svg | Caption2 = Schematic diagram of the human eye. (Iris labeled at upper right) | part_of = Front of [[eye]] | system = [[Visual system]] | Precursor = [[Mesoderm]] and [[ectoderm|neural ectoderm]] | Artery = [[long posterior ciliary arteries]] | Vein = | Nerve = [[long ciliary nerves]], [[short ciliary nerves]] | Lymph = }} The '''iris''' (plural: '''''irides''''' or '''''irises''''') is a thin, circular structure in the [[eye]]. It controls the diameter and size of the [[Pupil (eye)|pupil]]s. [[Eye color]] is the color of the iris. In humans, the iris may look green, blue, brown, hazel (a combination of light brown, green and gold), grey, violet, or even pink. In response to the amount of light exiting the eye, muscles attached to the iris expand or contract the pupil. The larger the pupil, the more light can enter the eye and reach the [[retina]]. [[File:Humaniris.jpg |thumb|left|250px|Iris colors are varied, this one orange round the pupil, then grey-greenish]] [[File:Picture of brown eyes.jpg|thumb|left|250px|Worldwide, brown and black are the most common colors]] {{-}} {{biology-stub}} [[Category:Eye anatomy]]