Red-green colour blindness in Singaporean children

Abstract

Purpose: X-linked red-green colour blindness is the most common form of colour blindness. Various studies suggest that, worldwide, 2-8% of men are afflicted with this condition. The purpose of this study is to determine the prevalence of red-green colour blindness in Singaporean schoolchildren. Method: A total of 1249 children aged 13-15 years were screened using the Ishihara 24-plate edition book during the School Cohort study of the Risk factors for Myopia visit. Results: A total of 1210 children (96.8%) managed to correctly identify at least 13 of the initial 15 plates and were deemed to have normal colour vision. Thirty-three children (32 boys, one girl) were only able to identify nine or less plates and were considered to be colour blind. Overall, 5.4% (95% confidence interval 3%, 7%) of Chinese, 4.9% (1%, 9%) of Malay and 4.9% (2%, 11%) of Indian boys were colour blind (P = 0.97). Classification plates 16-17 were useful in determining deutran or protan tendencies in only 14 (43%) of the 33 children identified as being colour blind. Conclusion: 5.3% of boys and 0.2% of girls were found to be colour blind in this Singapore-based study. Although the Ishihara test proved useful in identifying colour-blind children, other tests are required to accurately classify the types of red-green colour blindness in these children. © 2008 The Author Journal compilation © 2008 Royal Australian and New Zealand College of Ophthalmologists.