The perception of depth contours with yellow goggles

The ability of subjects to discriminate the depth of depressions in the snow was conducted at a cross-country ski area. The percentage of correct judgments on an overcast day was significantly greater with yellow goggles than with luminance-matched neutral goggles. This experiment, suggested by the chromatic-achromatic theory of color vision, indicates why yellow goggles are popular despite many previous unsuccessful attempts to prove their effectiveness.