1. A lighting device comprising:a mounting surface;
a lens comprising a lens body having an inner surface encapsulating a cavity and delimiting an entrance to said cavity, said entrance facing the mounting surface, the inner surface comprising a plurality of adjoining surface sections each defining a segment of the cavity, wherein each segment has a narrowing region distal to the entrance delimited by a curved portion of the surface section delimiting said segment; and
an elongate carrier extending from the mounting surface into the cavity segments through the cavity entrance and comprising a plurality of solid state lighting elements configured to emit light towards the lens body;
wherein the cavity comprises an elongate cross-section parallel to the cavity entrance.