The purpose of this project is to find out how does the iris work ? The eye is made up of several parts: the cornea, pupil, iris, lens, and retina. Each has an important function. You can see and put together a model of the eye in the Institute's Bioscience Exhibit. Ask the students Have you ever seen a picture of yourself where your eyes are red? This happens when the camera's flash reflects off the retina - or back wall - of your eye. The iris is the muscle that lets the proper amount of light through the pupil and into the eye. It opens when there is little light and closes when there is a lot. The students can illustrate this for another.