A lighting device comprising a plurality of light sources and a linear optical element, said optical element including: - a body of said optical element, wherein an internal surface of said body encloses said light sources, whereby light emitted by said light sources passes first through a first refraction surface (B') represented by said internal surface of said body, thereby entering said body, wherein the body comprises a total internal reflection surface and provides a light propagation path for light emitted by said light sources towards a light emitting surface of said optical element, - an insert coupled with said body, the insert interposed in said light propagation path, whereby: a) a first portion of said light exits a first refraction surface represented by an external surface of said body not being in contact with said insert, thereby exiting said optical element without passing through said insert; b) a second portion of said light passes a second refraction surface (B") represented by the external surface of said body being in contact with said insert, thereby entering said insert, said second refraction surface (B") of said body being complementary to the respective surface of said insert, wherein said second portion of the light passes a third refraction surface (B"') represented by an external surface of said insert, thereby exiting said insert and said optical element; wherein the optical characteristics of light emitted from said light emitting surface are a function of at least one of the shape, position, material and/or texture of said insert, wherein the refraction index of said body is smaller than the refraction index of said insert, whereby said insert represents a lens insert, which is configured to focus said second portion of the light exiting through said third refraction surface (B"'), and wherein said body has a diffusive behaviour. - a body of said optical element, wherein an internal surface of said body encloses said light sources, whereby light emitted by said light sources passes first through a first refraction surface (B') represented by said internal surface of said body, thereby entering said body, wherein the body comprises a total internal reflection surface and provides a light propagation path for light emitted by said light sources towards a light emitting surface of said optical element, - an insert coupled with said body, the insert interposed in said light propagation path, whereby: a) a first portion of said light exits a first refraction surface represented by an external surface of said body not being in contact with said insert, thereby exiting said optical element without passing through said insert; b) a second portion of said light passes a second refraction surface (B") represented by the external surface of said body being in contact with said insert, thereby entering said insert, said second refraction surface (B") of said body being complementary to the respective surface of said insert, wherein said second portion of the light passes a third refraction surface (B"') represented by an external surface of said insert, thereby exiting said insert and said optical element; wherein the optical characteristics of light emitted from said light emitting surface are a function of at least one of the shape, position, material and/or texture of said insert, wherein the refraction index of said body is smaller than the refraction index of said insert, whereby said insert represents a lens insert, which is configured to focus said second portion of the light exiting through said third refraction surface (B"'), and wherein said body has a diffusive behaviour. a) a first portion of said light exits a first refraction surface represented by an external surface of said body not being in contact with said insert, thereby exiting said optical element without passing through said insert; b) a second portion of said light passes a second refraction surface (B") represented by the external surface of said body being in contact with said insert, thereby entering said insert, said second refraction surface (B") of said body being complementary to the respective surface of said insert, wherein said second portion of the light passes a third refraction surface (B"') represented by an external surface of said insert, thereby exiting said insert and said optical element;