The iris is a circular, pigmented membrane that provides the eye its color and the opening in the center is the pupil of the eye.
The iris is made up of muscular fibers that control the amount of light entering the pupil so that you can see clearly. The iris accomplishes this task by making the pupil smaller in bright light and larger in dim light.
A prosthetic eye can help improve the appearance of people who have lost an eye to injury or disease. It's commonly called a "glass eye" or "fake eye."
The prosthetic eye includes:
oval, whitish outer shell finished to duplicate the white color of the other eye
round, central portion painted to look like the iris and pupil of the other eye
Implanting a prosthetic eye (ocular prosthesis) is almost always recommended after an eye is surgically removed due to damage or disease.