Relative yellow-blue sensitivity as a function of retinal position and luminance level.

Abstract

Relative sensitivity for yellow and blue was determined by hue cancellation, using the method of constant stimuli. Measurements were made with a 1° stimulus at the fovea, 2° above the fovea, and every 4° along the upper vertical meridian out to 18° at three luminance levels (0.5, 0.1, and 0.01 ft-L). Relative yellow–blue sensitivity remained much the same from fovea to periphery for the two highest light levels. At the lowest luminance level there was a slight increase in relative blue sensitivity in the near periphery and a progressive decrease in relative yellow sensitivity as the peripheral angle increased. The variability of color discrimination increased greatly as luminance decreased and the peripheral angle increased.