The purpose of this research is to evaluate novel technologies for the assessment of ocular structure and function, including the scanning device called Optical Coherence Tomography (OCT). We will test the OCT and other devices in their ability to image diseases of the eye and also compare the measurements made with OCT to those of other imaging and visual field devices approved by the Food and Drug Administration (FDA). OCT may be useful for the early diagnosis and monitoring of a variety of types of eye diseases