Frequency of Colour Vision Defects Among Zulus in Natal

Abstract

SummaryThe HRR test was used to study the frequency of colour vision defects in 297 Zulu men and 43 Zulu women of Natal, two Basuto men in Natal, and two Swazi men and 21 Swazi women in the Transvaal.The frequencies agree with the work of other authors, that the numbers of red–green defectives in the black populations of Africa are less than half those among European whites. The observed frequency of women defectives is greater than that expected from the number of males, and the difference is probably due largely to the inclusion of a small number of women with considerable heterozygous manifestation.No yellow–blue deficient subjects were found.