Central nervous system stimulants: effect on visual functions and occurrence of road traffic accidents.

OBJECTIVE To determine the influence of the use of central nervous system (CNS) stimulants on visual functions and occurrence of road traffic accidents (RTA) amongst commercial drivers. DESIGN A cross-sectional study in which two hundred and fifteen consecutive drivers were interviewed and their eyes examined. SETTINGS Ife Central Local Government Area (LGA) of Osun State, Nigeria. MATERIALS AND METHODS Out of the estimated 270 commercial drivers registered in the four major parks of the LGA, 215 consecutive drivers participated in the survey Questionnaires were administered by face-to-face interview and the drivers' eyes examined by the authors. RESULTS The prevalence of visual impairment (visual acuity < 6/18) in the better eye without correction was 3.3%, and there was a significant association between uncorrected visual acuity impairment in the better eye and RTA (p = 0.0152). The prevalence of refractive error was 8.4%, but none of these drivers wear corrective glasses. Alcohol consumption is common (57.7%) amongst the drivers, and there was a significant association between alcohol consumption and RTA (p = 0.00124). There was also a significant association between the use of CNS stimulants (kolanut, marijuana and cigarette) and RTA (p = 0.005). CONCLUSION It was therefore concluded that visual impairment in the better eye, alcohol consumption and the use of other CNS affecting substances contribute to the occurrence of RTA among the drivers.