The accuracy and reproducibility of three visual field screening methods for detecting glaucomatous visual field defects are being studied. Eligible patients are invited to participate in a randomized study that assigns a rotating order for the three visual field tests. The perimetrist is "masked." Each patient undergoes screening with all three methods on two separate days. The first of the visual field methods is a recently described computer-generated screening procedure (CGSP) that appears to identify quickly and accurately early glaucomatous visual field defects. The second of the visual field methods is the Clinical Branch glaucoma screening field (GSF) using suprathreshold kinetic and static techniques. The third is standard kinetic Goldmann perimetry.