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Heredity of Two Types of Normal Colour Vision


THE anomaloscope is used to diagnose red and green colour blindness and its four or six sub-types. In the apparatus the lower half of a circular plane is illuminated by a yellow light of wavelength 589 mµ, and in the upper half red (670 mµ) and green light (546 mµ) are mixed. It is possible, by changing the proportion of red and green illumination, to make the two halves look the same; the proportion of red and green lights required is called the Rayleigh equation, which is accepted by individuals with normal colour vision, but colour blind people react in different ways. On the anomaloscope which I used (model II, Schmidt and Haensch, Berlin) it is possible to change the wavelength of the monochromatic yellow light to make it more and more yellow green, or more and more orange, while the red and green lights are shifted in a similar manner. Rayleigh equations can be found for these wavelengths. I have built up a system of nine equations with the yellow light varying from 574 mµ to 603 mµ.

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WAALER, G. Heredity of Two Types of Normal Colour Vision. Nature 215, 406 (1967).

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