A lighting device comprising: a glass tube; a solid state lighting assembly in said glass tube, said assembly comprising: an electrically insulating optical film comprising at least one arcuate portion lining a part of the inner surface of the glass tube, wherein the glass tube further comprises a further part defining a light exit portion; and a plurality of solid state lighting elements on a carrier, said carrier contacting said optical film; a thermally conductive member (40, 42) in between at least a part of the solid state lighting assembly and the glass tube for thermally coupling the solid state lighting elements to the glass tube, characterised in that the lighting device comprises a transparent or translucent electrically insulating cover (50, 60) contacting the electrically insulating optical film and covering the solid state lighting elements and wherein the transparent or translucent electrically insulating cover comprises a further electrically insulating film extending from a first section of the electrically insulating optical film to a second section of the electrically insulating optical film such that the solid state lighting elements are enveloped by the electrically insulating optical film and the further electrically insulating film. a glass tube; a solid state lighting assembly in said glass tube, said assembly comprising: an electrically insulating optical film comprising at least one arcuate portion lining a part of the inner surface of the glass tube, wherein the glass tube further comprises a further part defining a light exit portion; and a plurality of solid state lighting elements on a carrier, said carrier contacting said optical film; a thermally conductive member (40, 42) in between at least a part of the solid state lighting assembly and the glass tube for thermally coupling the solid state lighting elements to the glass tube, characterised in that the lighting device comprises a transparent or translucent electrically insulating cover (50, 60) contacting the electrically insulating optical film and covering the solid state lighting elements and wherein the transparent or translucent electrically insulating cover comprises a further electrically insulating film extending from a first section of the electrically insulating optical film to a second section of the electrically insulating optical film such that the solid state lighting elements are enveloped by the electrically insulating optical film and the further electrically insulating film. an electrically insulating optical film comprising at least one arcuate portion lining a part of the inner surface of the glass tube, wherein the glass tube further comprises a further part defining a light exit portion; and a plurality of solid state lighting elements on a carrier, said carrier contacting said optical film; a thermally conductive member (40, 42) in between at least a part of the solid state lighting assembly and the glass tube for thermally coupling the solid state lighting elements to the glass tube, characterised in that the lighting device comprises a transparent or translucent electrically insulating cover (50, 60) contacting the electrically insulating optical film and covering the solid state lighting elements and wherein the transparent or translucent electrically insulating cover comprises a further electrically insulating film extending from a first section of the electrically insulating optical film to a second section of the electrically insulating optical film such that the solid state lighting elements are enveloped by the electrically insulating optical film and the further electrically insulating film.