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 is a thin, circular part inside your eye. Think of it like a tiny curtain that controls how much light gets in. It changes the size of your pupil, which is the black circle in the middle of your eye.

The color of your iris is what we call your eye color. Human irises can be many colors, like green, blue, brown, or hazel. Hazel eyes are a mix of light brown, green, and gold. Some people also have grey or even violet eyes.

The iris has tiny muscles. These muscles work to make your pupil bigger or smaller. When it's dark, your pupil gets larger to let in more light. When it's bright, your pupil shrinks to protect your eye from too much light. This helps your eye see clearly in different light conditions.

Images for kids

• 

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

• 

  Blue-green-gray eyes are quite rare. Their exact color can seem to change depending on what's around them.

• 

  Blue eyes of a 17-year-old.

• 

  Amber-colored eyes are very rare. They happen when there's more yellow pigment (lipochrome) in the iris and less dark pigment (melanin). This gives the eye an orange-gold color.

• 

  A blue iris with a yellow iris nevus, which is like an eye freckle.

• 

  An example of a green-brown (hazel) iris.

• 

  An example of a brown iris.

• 

  An example of heterochromia. One eye is brown, and the other is hazel.

• 

  The main parts of the eye.

• 

  The iris, seen from the front.

• 

  A special image showing the blood vessels in the iris.

See also

In Spanish: Iris para niños