A device and a method for automatically setting the luminance of a light beam emitted from a lighting device of a vehicle as a function of the range of vision. The device includes a device for ascertaining a current range of vision based on at least one first parameter, which represents a dimension of the current range of vision, an evaluation device for evaluating the ascertained current range of vision (SI) based on at least one second parameter as the evaluation criterion and outputting a corresponding evaluation variable, and a setting device for assigning a required luminance as a function of the ascertained current range of vision (SI) and the corresponding evaluation variable and setting the required luminance.