Photogrammetry will be used as an objective method to quantitate cupping of the optic disc for early detection of glaucoma and for monitoring the treatment of ocular hypertension (OH) and open-angle glaucoma (OAG). Efficacy of measurement of optic disc photographs by these methods will be determined for diagnosis of development of optic disc pathology and its reversibility as compared with a group of normal subjects followed for rates of change of optic discs and visual fields. In addition to following a number of subjects in our own medical facilities, photographs will be obtained from collaborators in major research centers in this country and abroad. This collection will determine the effectiveness of measurements in other institutions as well as increase the number of subjects for all studies.