FREQUENCY OF COLOUR BLINDNESS AMONG THE TRIBAL AND NON-TRIBAL PEOPLES OF ANDHRA PRADESH.

Abstract

SUMMARYA survey of colour blindness, using Ishihara plates (1960), in the tribals and non‐tribals, i.e. Hindus, Christians and Muslims, showed that 6‐5 % of the men among the non‐tribals, and 2–5 % among the tribals were colour blind. This difference is explained as due to relaxation of selection against colour blindness in the civilized communities. Out of 1155 tribals tested in the Polavaram Agency area of Andhra Pradesh, 966 were Koya Doras, 61 Konda Reddis, 51 Sugalis, 44 Koya Kammaras, 24 Pandava Nayakas, 6 Konda Rajus, and 3 Koya Musaras.We are grateful to Prof. J. B. S. Haldane, F.R.S. for his suggestions and financial help.An investigation of this nature could not have been carried out without the help of numerous people among whom we would especially like to mention the Karanam of Kondrukota, Mr K. Sarweswara Rao, Mr M. V. Krishna Rao, Mr I. Vasanta Kumar, and Mrs P. Meera Khan.