We collect ninety-five percent of all our input about the world around us through our sense of sight. This program describes how our eyes work and provides information about the nature of light and color. People have been fascinated with light and eyes for a long time but their ideas have not always been correct. For instance, two thousand years ago the Greeks thought that our eyes sent out rays of energy that struck an object and then returned to our eyes with information about the object. They thought this way because when they viewed the eyes of cats, dogs, and deer they noticed that the eyes of these animals were glowing. It was this glowing that they interpreted as a source of energy that was generated by the eyes. Today we know that our ability to see is totally dependent on reflected light. Light strikes an object and then some of it is absorbed and the rest is reflected or bounces off the object. It is this reflected light that enters our eyes.