A drunk driving prevention system for a vehicle includes an eye symptom detector adapted for supporting in the vehicle at a position to detect eye symptoms of a driver, a control module operatively linked to the eye symptom detector for determining and analyzing whether the eye symptoms of the driver match with alcohol influenced eye symptoms, and a signal module operatively linked control module for generating a drunk driving signal in response to the alcohol influenced eye symptoms that suspect an alcohol concentration of the driver is above a predetermined threshold.
