A method and system for detecting operator alertness of an operator of a vehicle or machine comprises an image processor and an analyzer. The image processor determines whether at least one eye of an operator is visible and determines whether the operator is generally facing forward with respect to the vehicle. The analyzer applies at least one of position analysis and motion analysis to a three dimensional representation of an operator to determine alertness of the operator if at least one eye of operator is not visible or If the operator is generally facing forward.