Abstract

For the past several years, we have been working to develop a new visual field testing technique, called Pattern Discrimination Perimetry, for which the patient is asked to detect a nonrandom pattern of dots embedded in a large surrounding field of random dots. The overall densities of the dots in the target and surround fields are equal, so the patient cannot use luminance cues to detect the target. The features that distinguish the target pattern from the surround can be either the spatial arrangement of dots, the way the dots change in time, or a combination of both. In general, the visibility of the target depends on the degree of nonrandomness, or coherence, of the target dots. To measure the patient's sensitivity to a pattern, we reduce its coherence by randomizing just enough of the target dots to make the pattern undetectable.

© 1990 Optical Society of America