Orientation of test-object affects visibility throughout visual field.

Abstract

ABSTRACT Luminance thresholds were obtained for narrow bars of light in vertical, horizontal, left oblique, and right oblique orientations. From 5° to 60° into the periphery, thresholds were significantly higher for the stimuli in oblique orientations. This situation remained in both light and dark‐adapted conditions, suggesting the problem pervades both rod and cone visual systems.