Colour Vision Defects: Awareness, Prevalence And Effects Among Secondary School Students In Imo State, Nigeria.

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.