A lighting device comprises a housing carrying a linear array of light radiation sources and one or more elongated diffusive screens arranged facing the array of light sources so as to be passed through by the light radiation. The screen or screens have a pattern of geometric features for producing a radiation pattern of the light radiation emitted by the lighting device as a result of passing through the diffusive screen or screens. By replacing the diffusive screen or screens with screens which have a different pattern of geometric features it is possible to vary the radiation pattern of the light radiation emitted by the lighting device.