Colour Blindness Among Male Professional Drivers: A Cross-sectional Study In Karachi

Objective: To determine the frequency of color blindness among male professional drivers of Karachi- Pakistan and thedifficulties they experience while driving.Study Design and Setting: A cross-sectional study was conducted aomng 300 male drivers with valid driving licensesoperating on local and long routes in Karachi.Methodology: The study was done at various locations in the city of Karachi from September to November 2017. Thesubjects were tested for vision and color blindness with the help of Snellen’s chart and Ishihara chart respectively. A precisedquestionnaire was developed keeping in view the study objectives. SPSS version 21.0 was used for data entry and itsanalysis. Each questionnaire was thoroughly studied and seen for missing data or information before entry. A writteninformed consent about the study was provided to the subjects in the form of a plain language statement attached to thequestionnaire. This study was approved by the ethical review board of Karachi Institute of Medical Sciences (KIMS).Results: Amongst the 300 participants 7 (2.33 %) of the drivers were found to have complete color blindness while 2(0.66%) were partially colour blind. They preferred day time driving and experience difficulties in recognizing trafficsignals and vehicle lights.Conclusion: The frequency of colour blindness was found to be low but it was observed that colour blind drivers face alot of difficulties while driving. Therefore, easy and practical changes should be made, like shape-coding of signals, andcontinuous research-based modifications are required to aid these drivers.