Is iris at the back of the eye?
The iris is not at the back of the eye. The structure at the back of the eye (on the inside) is called the retina. That’s the part that senses light. The iris is a structure at the front of the eye, consisting of a ring of muscle with an opening in the center, called a pupil. The iris can shrink the pupil, to admit less light, or expand the pupil to a larger size to admit more light. Eye color is deterimned by the iris. It is the only colorful muscle.