Luminosity Curves of Populations of Class I and Class II Normals in Colour Vision

Abstract

18 Class I and 18 Class II male subjects for unique green point who had normal colour vision had their luminosity curves measured for 8 points in the spectrum on a Wright Colorimeter for a 2° field. The results confirm earlier findings on fewer subjects, i.e., that the Class II subjects had a consistently lower luminosity at about the 565-nm point in the spectrum. Further data were collected whereby the luminosity of subjects exhibiting the various types of colour defect were taken for this region of the spectrum to see whether the characteristic of the curves, at different levels of luminance of the comparison field, corresponded to the characteristics of the Class I and Class II cases. A new visual pigment model to account for the Unique Green Phenomenon and colour-vision defect data is proposed.