The part that we can see is only just the front. That coloured circle is called the iris and the black spot in the middle is the pupil. This is the part of the eye that lets the light in.

Pupil size is controlled by the brain, which receives signals from each retina and sends a message for your eyes to adjust to the light. Muscles in the colored part of your eye, your iris ...

MIT engineers have made a breakthrough in this area—they’ve developed a method to grow muscle tissue that contracts in ...

The uvea is made up of a layer of blood vessels, a muscular ring that surrounds your pupil, and the iris, the colored part of your eye. Together, they help your eyes focus so you can clearly see ...

Medically reviewed by Christine L. Larsen, MD The pupil is the opening located in the center of the iris of the eye. It ...