Dichoptic color fusion studied with wavelength discrimination

In order to investigate dichoptic color mixture, wavelength discrimination thresholds were measured in the presence of a dichoptically added field. The dichoptically added field was a 1.1 degrees bipartite field identical to the discrimination field, its wavelength being equal to the standard wavelength of the discrimination field. The discrimination thresholds were measured in dichoptic viewing covering a range from 450 to 650 nm. It was found that discrimination was deteriorated in the presence of the dichoptically added field for all the wavelengths used. However, the deterioration was largely independent of the luminance of the added field. These results suggest that: (a) central color fusion indeed occurs but, (b) additive color mixture fails in dichoptic mixing.