Multiple choice

Which portion of the eye contains the brown pigment melanin, and is responsible for regulating the size of the pupil?

  1. Retina

  2. Iris

  3. Sclera

  4. Choroid

  5. Macula

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The iris appears as the colored part of the eye, and is responsible for regulating the size of the pupil which in turn influences the amount of light that enters the eye. Melanin is responsible for the color of our eyes. The iris is made up of blood vessels and connective tissue in addition to melanocytes and other pigmented cells that are responsible for its distinctive color. The melanocytes contain melanin, a brown or black pigment.