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iris

(I-ris)
The colored tissue at the front of the eye that contains the pupil in the center. The iris helps control the size of the pupil to let more or less light into the eye.
Eye anatomy; two-panel drawing showing the outside and inside of the eye. The top panel shows the outside of the eye, including the eyelid, pupil, sclera, and iris. The bottom panel shows the inside of the eye, including the cornea, lens, ciliary body, retina, choroid, optic nerve, and vitreous humor.Enlarge this image in new window
Anatomy of the eye showing the outside and inside of the eye, including the eyelid, pupil, sclera, iris, cornea, lens, ciliary body, retina, choroid, optic nerve, and vitreous humor.
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