Patients will undergo a medical history and physical examination. A blood collection of about 4 tablespoons will be done to measure the amount of lutein and other vitamins in the blood. Patients will have a complete eye examination consisting of procedures standard to those given by ophthalmologists. Participants will have photographs taken of their eyes, and they will undergo a visual field test. Flicker photometry also will be conducted. This consists of the patients looking at a flashing bluish light with one eye at a time, and turning a knob until the light stops flashing. Then during the test, patients will look away from the light and turn the knob until the flashing stops.