Lighting device comprising a light source and a light guide, the light guide comprising: - an entry optical interface configured to allow the entry of the light emitted by the light source illuminating the entry optical interface, - an exit optical interface configured to allow the light to exit from the light guide, the light guide furthermore comprising: - lateral optical interfaces (43, 44) forming opposing surfaces, and - at least one blind hole disposed between the entry optical interface and the exit optical interface, said blind hole being formed starting from at least one indentation in one of the surfaces forming a lateral optical interface and configured so as not to open out onto the opposing surface forming a lateral optical interface, the edges of the blind hole forming secondary optical interfaces (32, 34), the device furthermore comprising at least one additional optical interface facing at least one secondary optical interface (32, 34), and configured such that: - light rays propagating within the light guide and incident on the additional optical interface are reflected by said additional optical interface in the direction of the exit optical interface, and - light rays propagating within the light guide and incident on the secondary optical interface are reflected by said secondary optical interface in the direction of the additional optical interface, characterized in that the device is configured such that: - at least 50 % of the light rays propagating within the light guide and incident on the additional optical interface is reflected by said additional optical interface in the direction of the exit optical interface, and - at least 50 % of the light rays propagating within the light guide and incident on the secondary optical interface is reflected by said secondary optical interface in the direction of the additional optical interface. - an entry optical interface configured to allow the entry of the light emitted by the light source illuminating the entry optical interface, - an exit optical interface configured to allow the light to exit from the light guide, - lateral optical interfaces (43, 44) forming opposing surfaces, and - at least one blind hole disposed between the entry optical interface and the exit optical interface, said blind hole being formed starting from at least one indentation in one of the surfaces forming a lateral optical interface and configured so as not to open out onto the opposing surface forming a lateral optical interface, the edges of the blind hole forming secondary optical interfaces (32, 34), - light rays propagating within the light guide and incident on the additional optical interface are reflected by said additional optical interface in the direction of the exit optical interface, and - light rays propagating within the light guide and incident on the secondary optical interface are reflected by said secondary optical interface in the direction of the additional optical interface, - at least 50 % of the light rays propagating within the light guide and incident on the additional optical interface is reflected by said additional optical interface in the direction of the exit optical interface, and - at least 50 % of the light rays propagating within the light guide and incident on the secondary optical interface is reflected by said secondary optical interface in the direction of the additional optical interface.