The object of the invention is to provide lighting for the rotor blade tips, which is more reliable than that proposed hitherto, wherein any damage which occurs is no longer so complicated and expensive to rectify as hitherto, but can be rectified extremely swiftly. A rotor blade of a wind power installation with a rotor blade connection to a hub of the wind power installation and a rotor blade tip at the end of the rotor blade, which is in opposite relationship to the rotor blade connection, characterized in that at least one light waveguide is laid from the rotor blade connection to the rotor blade tip. The light can be modified to be on only when the blade is at the top portion of the rotation, such as between the 9:00 and 3:00 positions, or the 10:00 and 2:00 positions.