Drowsiness detection system and method

A low-cost system for detecting a drowsy condition of a driver (18) of a vehicle (10) includes a video imaging camera (20) located in the vehicle (10) and oriented to generate images (30) of a driver (18) of the vehicle (10). The system also includes a processor (32) for processing the images (30) acquired by the video imaging camera (20). The processor (32) monitors an eye (22) and determines whether the eye (22) is in an open position or a closed state. The processor (32) further determines a time proportion of eye closure (PT) as the proportion of a time interval that the eye (22) is in the closed position, and determines a driver drowsiness condition when the time proportion of eye closure (PT) exceeds a threshold value (T1).