Patients 4 and older who have glaucoma or related diseases or whose family members have those diseases may be eligible for this study. They will complete a medical history for the doctors to verify the diagnosis, inquire about medical problems and surgical operations, and gather data about vision problems in a patient's family (by drawing a family tree). The complete eye examination may take several hours. Eye drops will be used to dilate, or enlarge, the pupils of patients' eyes, and the pupils will stay dilated for 4 to 6 hours. There may be some temporary glare in brightly lit areas, which can be reduced by wearing of sunglasses. Patients may experience some blurring of vision. There may be a localized allergic reaction to the medication used or an increase of pressure inside the eye. If that occurs, medication to control the reaction will be given. In addition, photographs of the retina and perhaps even the lens will be taken. For that procedure, eye drops will dilate the pupils of the eyes. The light that is involved with the specialized photography may cause some mild discomfort. Patients will undergo eye tests regarding color vision, field of vision, and ability to see the dark. Also, there will be a measurement of pressure in the eye and thickness of the cornea.