Iris (anatomy)

Iris
The iris in humans is the colored (typically brown, blue, or green) area, with the pupil (the circular black spot) in its center, and surrounded by the white sclera.
Schematic diagram of the human eye (iris labeled at upper right)
Details
Precursor	Mesoderm and neural ectoderm
Part of	Front of eye
System	Visual system
Artery	Long posterior ciliary arteries
Nerve	Long ciliary nerves, short ciliary nerves
Identifiers
Latin	iris
MeSH	D007498
TA98	A15.2.03.020
TA2	6753
FMA	58235
Anatomical terminology [edit on Wikidata]

The iris (pl.: irides or irises) is a thin, annular structure in the eye in most mammals and birds that is responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm. Eye color is defined by the iris.