Iris (eye) facts for kids

Quick facts for kids Iris
The iris is the blue area. Other structures are the pupil center and the white sclera surrounding the iris. The overlying cornea is there, but not visible, as it is transparent. Also pictured are the red-colored blood vessels within the sclera.
Schematic diagram of the human eye. (Iris labeled at upper left.)

The iris (plural: irides or irises) is a thin, circular structure in the eye. It controls the diameter and size of the pupils.

Eye colour is the colour of the iris. In humans, the iris may look green, blue, brown, hazel (a combination of light brown, green and gold), grey or violet. In response to the amount of light entering 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.

Images for kids

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  Anterior chamber cross-section imaged by an SD-OCT.

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  Among human phenotypes, blue-green-gray eyes are a relatively rare eye color and the exact color is often perceived to vary according to its surroundings.

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  Blue eyes of a 17 year old.

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  Adult male with amber-colored eyes: This color is extremely rare and occurs when an unusually stronger presence of the yellow pigment (lipochrome) exists in the iris, with a rather small amount of pigment (melanin). This gives the eye an orange copper/gold hue.

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  Example of a blue iris featuring a yellow iris nevus (eye freckle)

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  Example of a green-brown (hazel) iris

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  Example of a brown iris

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  Example of heterochromia - one eye of the subject is brown, the other hazel.

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  Structures of the eye

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  Iris, front view

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  Fluorescein angiograpy of the iris reveals a radial layout of blood vessels.

See also

In Spanish: Iris para niños