The present disclosure refers to a light module, comprising a lens unit, which is formed with a bottom, a lid and one or more side walls between the bottom and the lid, wherein the one or more side walls provide one or more insertion openings; a printed circuit board unit, which carries one or more light sources and is inserted into the lens unit through a first insertion opening of the one or more insertion openings such that light emitted by the one or more light sources exits the light module through the bottom and/or the lid of the lens unit; and a housing unit, which is provided with a bottom opening, a lid opening and one or more side walls between the bottom opening and the lid opening, wherein the lens unit is arranged within the housing unit such that the bottom opening of the housing unit is closed by the bottom of the lens unit, the lid opening of the housing unit is closed by the lid of the lens unit, and the one or more insertion openings of the lens unit is closed by the one or more side walls of the housing unit. It also refers to an external rear view device with such a light unit.