I A major cause of visual disability, macular degeneration degenera-tion is still a mystery to most Americans. The area of the eye affected is the macula a tiny part of the retina lining the back of the eye. In normal vision, light passes through the eye and strikes the retina, a sensitive network of nerves. In macular macu-lar degeneration, the macula loses its ability to function efficiently, affecting central vision. In most cases the process is not sudden, but progresses gradually. People affected by the disease find it difficult to see at long distances such as when driving, to do close 4M work, to see faces clearly or distinguish different colors. Anyone experiencing a loss of vision should have a thorough eye examination. For more information, write to your state Society to Prevent Blindness or the National Society to Prevent Blindness, 79 Madison Avenue, New York, N.Y. 10016.