The driver’s advanced visual ability to adapt quickly and efficiently to sudden changes in light levels, whether when transitioning from bright daylight to dark environments such as in a tunnel, or when driving at night after exposure to bright light. This adaptation involves the eye’s ability to adjust retinal sensitivity and recognize fine details of the road situation in a variety of light conditions, ensuring safe and balanced road behavior. In the psychology of road behavior, visual adaptation to light and darkness is a key factor for rapid response to emergencies, recognizing traffic lights, other vehicles and pedestrians, and taking timely preventive measures. A lack of this ability leads to slower reaction times, a reduced ability to preemptively assess risks, and an increased likelihood of collisions or accidents, especially when driving at night or when exposed to direct light radiation. Visual adaptation to light and dark is therefore considered a critical indicator of driver competence and is used as the basis for psychological and neuropsychological assessment programmes, night driving training and the development of road safety recommendations to improve visual alertness and protect all road users.