Aim: To determine the prevalence, pattern and impact of colour vision defects among public secondary school students in Enugu, Nigeria with a view to guiding the affected students on appropriate career choice. Methods: A descriptive cross-sectional study was carried out among students attending public secondary schools in Enugu-East Local Government Area, Enugu state. A total of 950 students (361 males, 589 females) were selected by multistage sampling. The students were assessed for colour vision using Ishihara 38 plate edition and Farnsworth D-15 colour caps. An interviewer-administered structured questionnaire was used to obtain the socio-demographic data and impact of colour vision on colour-related school tasks and activities of daily living. Data was analysed using statistical package foe social sciences, version 20. Result: The age of the students ranged from 10-20 years with mean age of 14.2 ± 1.9 years. Eleven (1.2%) students were found to have colour vision defect out of whom 9 were boys and 2 were girls, 6 (54.5%) were deutan and 5 (45.5%) were protan. No tritan defect was detected. Greater percentages of the students with colour vision defect had difficulties with colour-related school tasks and daily activities when compared to those with normal colour vision. Conclusion: Colour vision defect may affect students’ performance in colour-related school tasks and activities of daily living. Therefore, early detection of colour vision defect is important so as to guide in the choice of future career