Spectral unique hues (blue, green, and yellow) were determined for 50 observers ranging in age from 13 to 74 years. Each unique hue was measured at three luminance levels (0.5-log-unit steps). There were no significant changes in the spectral locations of red–green equilibrium hues (unique blue and yellow) as a function of luminance level or age. In contrast, significant shifts in unique green loci occurred as a function of both age and luminance. Unique green loci shifted toward shorter wavelengths with age. These results are consistent with the hypothesis that with advancing age there is a parallel decline in the input of all three cone types to the red–green chromatic channel and either a selective decline in short-wave-sensitive cone input to the yellow–blue chromatic channel or a change in the way in which cone signals are combined within the yellow–blue channel.
© 1990 Optical Society of America
Original Manuscript: May 22, 1989
Manuscript Accepted: September 6, 1989
Published: February 1, 1990
Brooke E. Schefrin and John S. Werner, "Loci of spectral unique hues throughout the life span," J. Opt. Soc. Am. A 7, 305-311 (1990)