Abstract: A nonimaging lens consists of a solid body of light-propagating material defining a first light-refracting surface, a second light-reflecting surface and a third light-refracting surface. To redirect the generally parallel light rays of a directional light beam, the first light-refracting surface diverges the light rays of this beam, the second surface reflects the divergent light rays, and the third surface refracts these reflected light rays. To concentrate dispersed light rays into a generally directional light beam, the third surface first refracts the light rays, the second light-reflecting surface converges these refracted light rays, and the first surface refracts the convergent light rays toward the generally directional light beam. In accordance with one embodiment, the first light-refracting surface and the second light-reflecting surface are conical, open out in opposite directions, and respectively define skewed refraction and reflection axes.