Study of colour blindness in Jat Sikhs.

Of the 1306 male and 791 female Jat Sikhs of Patiala city and the surrounding villages between the age group 10-60 years, 50 males and one female were found to be having colour blindness, showing an incidence of 3.83% and 0.13% respectively. The study was done with the help if Ishihara Charts and Pickford Nicolson's anomaloscope. The type of colour blindness in males in its descending order of occurrence was simple deutranomaly 0.92%, extreme deutranomaly 0.77%, protanopia 0.69%, simple protanomaly 0.61%, deutranopia 0.61%, extreme potanomaly 0.15% and tritanopia 0.08%. The sole colour blind female was simple deutranomaly type. The incidence and type of colour blindness found in males are within the range of other Indian samples. Nevertheless the incidence is much lower than the values reported in other European populations.