Abstract: The invention relates to a device and a method for supplying information to pilots, especially in poor visibility, about, for instance, the borders of a runway (1). Along the long sides of the runway and at its beginning and end, signal means (2, 5) are arranged, which are translucent to e.g. UV radiation and which comprise a fluorescent material which converts the radiation penetrated by illumination into visible light. In the daytime, the UV radiation originates from sunlight. The converted light will then reinforce the usual light from the signal means, which originates from the sun's illumination thereof with visible light. As a result, It will be much easier to observe the signal means especially against the light. It is further suggested according to the invention that at night the signal means are illuminated by UV searchlights (34, 35).