A lighting device that can be used in at least two operating modes, viz. B1 for a free viewing mode and B2 for a restricted viewing mode, comprising - a backlighting system of planar extension that in operating mode B2 for a restricted viewing mode radiates light in a restricted angular range, wherein the light emitted by the backlighting system is, in at least one direction situated at an angle greater than 45 degrees relative to the surface normal of the backlighting system, radiated with no more than 10% of the maximum luminous intensity, - a plate-shaped optical element situated in front of the backlighting system as seen in the viewing direction, and - illuminants arranged laterally at the narrow sides of the optical element, - wherein - the optical element is configured as a light guide, which consists of a matrix plastic A and, homogeneously distributed therein, scattering particles of a polymer B, - the share of the scattering particles consisting of polymer B is 0.01 to 3 weight-percent relative to the matrix plastic A, - the refractive index nD of the polymer B is at least 0.01 units above the refractive index nD of the matrix plastic A, - and the light guide is transparent to at least 80% of the light emitted by the backlighting system, - so that, for a free viewing range in operating mode B1, the light laterally incident on the optical element from the illuminants is, in directions situated at angles greater than 45 degrees relative to the surface normal of the backlighting system, radiated with at least 20% of the maximum luminous intensity, - wherein, in operating mode B2, the backlighting system is switched on and the illuminants are switched off, and wherein, in operating mode B1, the illuminants are switched on and the backlighting system is switched off. - a backlighting system of planar extension that in operating mode B2 for a restricted viewing mode radiates light in a restricted angular range, wherein the light emitted by the backlighting system is, in at least one direction situated at an angle greater than 45 degrees relative to the surface normal of the backlighting system, radiated with no more than 10% of the maximum luminous intensity, - a plate-shaped optical element situated in front of the backlighting system as seen in the viewing direction, and - illuminants arranged laterally at the narrow sides of the optical element, - wherein - the optical element is configured as a light guide, which consists of a matrix plastic A and, homogeneously distributed therein, scattering particles of a polymer B, - the share of the scattering particles consisting of polymer B is 0.01 to 3 weight-percent relative to the matrix plastic A, - the refractive index nD of the polymer B is at least 0.01 units above the refractive index nD of the matrix plastic A, - and the light guide is transparent to at least 80% of the light emitted by the backlighting system, - so that, for a free viewing range in operating mode B1, the light laterally incident on the optical element from the illuminants is, in directions situated at angles greater than 45 degrees relative to the surface normal of the backlighting system, radiated with at least 20% of the maximum luminous intensity, - the optical element is configured as a light guide, which consists of a matrix plastic A and, homogeneously distributed therein, scattering particles of a polymer B, - the share of the scattering particles consisting of polymer B is 0.01 to 3 weight-percent relative to the matrix plastic A, - the refractive index nD of the polymer B is at least 0.01 units above the refractive index nD of the matrix plastic A, - and the light guide is transparent to at least 80% of the light emitted by the backlighting system, - so that, for a free viewing range in operating mode B1, the light laterally incident on the optical element from the illuminants is, in directions situated at angles greater than 45 degrees relative to the surface normal of the backlighting system, radiated with at least 20% of the maximum luminous intensity, - wherein, in operating mode B2, the backlighting system is switched on and the illuminants are switched off, and wherein, in operating mode B1, the illuminants are switched on and the backlighting system is switched off.