Prevalence of congenital color deficiencies in secondary-school students in Tehran.
A population-based study was conducted to determine the prevalence of color deficiencies in secondary-school students (ages 12-14) in Tehran. A total of 2,058 students (1,136 males, 922 females) were examined with Ishihara pseudoisochromatic color plates. In the study population, 97 cases of defective color vision were detected, including 93 males and 4 females. The affected individuals all had negative histories of previous systemic and ocular disease or chronic use of medications. The visual acuity was 20/20 and the fundus was normal in all affected students. Of the 93 cases of defective color vision in males (8.18%), 56 cases (4.93%) involved deuteranomaly, 13 (1.14%) protanomaly, 13 (1.14%) deuteranopia, and 11 (0.97%) protanopia. The four cases in females (0.43%) involved deuteranomaly in three cases (0.32%) and protanomaly in 1 case (0.11%). Deuteranopia and protanopia were not detected in females. This is the first study to determine the prevalence of congenital color blindness in Iran. The results agree with reports of prevalence of congenital color blindness from Western Europe.