Visual function is crucial in driving and is one of the links which determine the medical aptitude to this activity. The ophthalmologist has important medical and moral responsibilities and has more than one mission in the determination of the aptitude to driving. The evaluation of the aptitude of the (future) driver is based on different legal criteria (Belgian Royal Orders dated on 23-03-1998 and 05-09-2002) whose requirements are in accordance with EC reglementation and are different according as the motor vehicles are used for private or professional purposes. Social and psychological consequences of driving incapacity may be important as far as the real impact of vision alterations on the incidence of motor vehicle crashes is still to be clearly determined. The knowledge of the repercussions of different diseases such as ametropia, age related effects, loss of vision in one eye, cataract, glaucomatous neuropathy, laser treatments,... on car driving can help the ophthalmologist to improve his judgment on the patient's real driving aptitude and the quality of his counselling if needed.