BACKGROUND

Colour vision defect (CVD) is a public health issue with approximately one in ten males exhibiting some form of colour deficiency. Colour is used extensively in education so CVD has a dramatic impact on the learning, educational and social potentials of children. Racial differences have been reported with higher values noted amongst people of European ancestry.

OBJECTIVE

This study aims to assess CVDs, their magnitude and impact on the daily activities of secondary school students in Imo State, Nigeria.

MATERIALS AND METHODS

This was a multistage, cross-sectional, descriptive study which assessed the prevalence and effect of congenital CVD on secondary school students in Imo state using a questionnaire modified and adapted for this purpose. Colour vision was tested uniocularly for each student under bright illumination using the 38-plate Ishihara colour vision chart and Lanthony D-15 colour panel. The test was administered on a black background between the hours of 10 a.m. and 2 p.m.

RESULTS

Eight hundred and twenty-eight secondary school students were studied with a mean age of 15 ± 1.89 years. There were 468 males (57.0%) and 360 females (43%) with a male-to-female ratio of 1.3:1. There was a 3% prevalence of CVD. More males were significantly affected than females. Deutan defect was more common and none of the students had tritan defect.

CONCLUSION

There is a low level of awareness of congenital CVD. This disorder resulted in various degrees of difficulty with colour-related school and daily living tasks. Advocacy to government and schools is needed to create awareness of CVDs and offer early counselling to those affected.