Prevalence of Congenital Colour Vision Deficiency in Nigerians Living in Ugep, Cross River State

ABSTRACT Colour vision deficiency and colour blindness are synonymous terms describing poor colour discrimination by the visual senses. Congenital colour vision defects are common, x-linked inherited, non-progressive and untreatable disorders. Elsewhere, screening for these disorders are an established practice so that those affected can be advised about occupational preclusions. However, population-based study on the broader impact of colour vision defects is limited. A descriptive crosssectional survey was conducted using Plates 1-17 of the 2008 edition of the Ishihara’s colour album. The study was undertaken in Ugep, a rural community in Cross River State, Nigeria. A convenient sample of 1500 male and female subjects ranging from 10-60 years of age was used and the selection was based on cluster sampling. The study reveals that the prevalence of congenital colour vision deficiency in Nigerians living in Ugep is 1.87%(28 of 1500 subjects) and that of total colour blindness is barely 0.20%. The gender distribution of colour blindness in the sample 2.8% for males and 0.7% for females indicates a significantly greater frequency of defect among males than females (p