Color perimetry.

Seven subjects were studied to determine the reproducibility of color isopters utilizing a Tubingen perimeter with targets equated for radiant energy and separate for heterochromatic flicker luminance. Achromatic threshold recognition of targets for equal luminance gave smaller isopters with longer wavelengths (red). Color recognition thresholds, on the other hand, showed large blue, midzone red and green, and small yellow isopters. The target recognition and color recognition thresholds for equal energy targets gave smaller red isopters. The data support Traquair's contention that all color isopters would be equivalent if hue, saturation, and intensity were equated. Clinically, the detection of subtle peripheral and central field defects might reside in the use of appropriately selected equally bright-colored targets.