Each individual will be thoroughly evaluated during the screening process to determine if they are suitable candidates for inclusion in any of the NEI ongoing studies. The screening evaluation will include past and current medical histories, and an appropriate physical examination. Other routine diagnostic procedures and tests may also be completed in order to help determine a subject's eligibility. These tests and procedures are of minimal risk. Once the screening process is completed and their eligibility assessed, the subjects will be informed of their options to participate in one or more of the current clinical research studies. If no appropriate protocol is identified, recommendations for other treatment options may be given to the individual, their primary doctor or referring physician.