color blindness in male drivers referred to samenol-a'emeh clinic (2005-2008)

background: color blindness is an inherited disorder in which a person cannot distinguish colors from each other.  color blind drivers are involved in car accident twice as much as others. according to the importance of identifying causes of a lot of car accidents in iran and shortage of similar studies in this regards, this research was done to study the prevalence of color blindness in drivers. methods: in this cross-sectional study all drivers (28009)- who referred to optometry unit of samen-ol-aeme clinic of kermanshah in 2005- 2008 - were examined by ishihara test. data was analyzed using spss software and descriptive statistics. results: from 28009 drivers in this research just 784 individuals (2.88%) were diagnosed as color blind. the most types of color blindness were deuteranopia (55.4%), red-green (20.7%), and protanopia (14.2%) respectively. also during 2005 and 2006 the prevalence of color blindness was 3.23%, in 2007 was 3.02% and in 2008 this prevalence decreased to 1.93%. conclusion: the prevalence of color blindness in this study was lower than similar studies, but with regard to its relation with car accidents, it is suggested that authorities pay attention to screening of color blindness in drivers.