The wave theory of light gave Fresnel rein to a number of inventions in optics. These included the Fresnel mirrors (canted to produce an interference pattern), the Fresnel rhomb (produces elliptical polarization using internal reflection), and most importantly, the Fresnel lens, which uses a stepped geometry to produce focussing. The lens shown above are plastic and can be used for magnification or for solar radiation concentration. Fresnel lenses are used in automobile headlights and large glass Fresnel lenses are used in lighthouses and have been instrumental in the prevention of shipwrecks.