A method for determining the distance of visibility for a driver of a vehicle in the presence of an element disrupting the visibility of the driver, the method comprising the following steps: determining the luminosity of the pixels of a region of an image taken in the field of vision of the driver, resulting in a luminosity curve, determining a first tangent to the curve of luminosity, determining a second tangent to the curve of luminosity, determining a sweep-line according to the first tangent and second tangent, the sweep-line being representative of the distance of visibility.