Naming of Groups with Normal Colour Vision

Abstract

ONE of us has described the heredity of normal colour vision¹. In a publication on colour vision and its defects, the other² has discussed the parallelism between the symptoms of deuteranomaly and protanomaly and stressed particularly the bimodality which is seen in almost all of the colour assessments of the two groups. It is often the case that comparable colour judgments or colour experiences in deuteranomaly are connected with a longer wavelength, and in protanomaly to a shorter one. A few examples can be mentioned. Rubin³ found that the spectrum locus of pure yellow is at 583 nm for deuteranomals and at 563 for protanomals; for “balanced” orange his respective values were 612 and 590 nm and for pure green they were 520 and 502 nm. Chapanis⁴ noted a similar bimodality of the locus of maximum desaturation in the spectrum of the red and green anomalies at about 500 nm in deuteranomaly and at about 490 nm in protanomaly, while Jameson and Hurvich⁵ found the same type bimodality in the wavelength discrimination curves of these subjects (in the locus of their maximum sensitivity to the change of wavelength). Even their maxima of light sensitivity show this bimodality (see, for example, ref. 6). Clearly, deuteranomaly and protanomaly arc independent defects of either a red or a green sensory process. They are merely subtypes of a single defect of red and green colour vision and possibly depend on two kinds of mutation at the same chromosomal locus^7,8.