Circumferentially emitting luminaires and lens elements formed by transverse-axis profile-sweeps

An illumination lens comprising: a two-dimensional beamforming lens-profile having an output surface and an input surface, where the profile acts to deflect light rays from a light source into a relatively narrow output beam; the lens-profile encloses a zone of higher refractive index than that of the area outside the profile where the higher refractive-index zone admits the light rays; a transverse axis of revolution and symmetry which extends transversely to the lens-profile; a surface of revolution formed by circularly sweeping the lens-profile about the axis of revolution forming a circumferential beam from the output beam emitted by said surface of revolution, characterized in that the output surface comprises a curved outer surface adapted to totally internally reflect light beams entering the lens through the input surface and refract light beams that have been internally reflected.