Assessment of Visual Acuity and Colour Vision Deficiency Among Commercial Drivers in Onitsha, South East Nigeria

Background: Road traffic crashes remain a leading cause of injury and death in Nigeria, and impaired visual function among commercial drivers is a frequently overlooked contributing factor. Colour vision deficiency, though often undetected, can compromise traffic signal interpretation, increasing accident risk. In commercial hubs such as Onitsha, Anambra State, large volumes of drivers operate without vision screening. Objectives: This study aims to assess visual acuity and screen for colour vision deficiency among commercial drivers in Onitsha and to determine the proportion with clinically significant visual impairment. Methods: Two hundred commercial drivers will be recruited from major motor parks using systematic random sampling. Visual acuity will be tested using a Snellen chart at six metres. Colour vision will be assessed with Ishihara pseudoisochromatic plates. Frequency distributions and chi-square tests will describe and compare data by driver category and years of service. Expected Outcomes: A significant proportion of drivers are anticipated to have uncorrected reduced visual acuity, with colour vision deficiency more prevalent among older drivers. Conclusion: Findings will support advocacy for mandatory vision screening as a prerequisite for commercial driving licensure in Nigeria. Keywords: visual acuity, colour vision deficiency, commercial drivers, Onitsha, road safety.