Abstract: The present invention provides a method for establishing fixation during computerized visual field perimetry, requiring the subject to fixate on a stationary target for a brief instance as he/she moves a secondary target towards the stationary target. In a preferred embodiment, the subject interactively moves the secondary target in the shape of crosshairs toward the stationary fixation target displayed on a monitor using the operations of a computer mouse. The stationary fixation target has preferably the shape of a small red circle in order to make it readily identifiable by the subject. The computer mouse pointer when contacted attaches itself to the secondary target. The subject then moves his head so that the fixation target is directly in front of him/her, and, while staring at the fixation target, moves the secondary target towards the stationary fixation target.

Abstract: A novel psychophysical visual test based on the visual response of the eye to alternating chromatic complementary colors or achromatic grays of varying saturation, luminance and/or contrast is proposed for the early detection of glaucoma, and other diseases. In one embodiment, although the luminance level remains constant, the visual stimulus alternates between two complementary or counter phase colors, preferably against a gray background at about 40 times a sec, for example, between blue and yellow. When the colors are alternated in this manner, the visual stimulus appears white or gray to an observer, instead of either blue or yellow. As the saturation is reduced, however, the alternating colors appear grayer, and then eventually cannot be perceived. Persons suffering from glaucoma and other diseases, however, find it more difficult than normal people to distinguish the visual stimulus as the saturation and/or luminance is reduced.