NOVELTY - Making a lens (100), involves providing glass carrier (102), providing at least partially transmissive layer (104) on first surface of glass carrier (106); forming slope facets coupled together by draft facets on a surface of partially transmissive layer; identifying geometric errors in the slope facets and draft facets of the partially transmissive layer to create correction factors; and forming corrected slope facets coupled together by draft facets on a surface of a second at least partially transmissive layer on a surface of second glass carrier (108) using correction factors.    USE - For making lens (claimed), particularly to the fabrication of high performance silicone-on-glass Fresnel lenses (claimed).    ADVANTAGE - The method provides a lens that does not suffer from the performance degradation of the prior art; allows the formation of sharp peaks and valleys which results in a higher performing lens. The machine tool has a high structural stiffness, high positional accuracy and repeatability of the rotational and translation axes, and ample vibration isolation.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) lens comprising a glass carrier, and an at least partially transmissive layer on a surface of the glass carrier, where the at least partially transmissive layer has slope facets coupled together by draft facets on its surface, where the slope facets coupled together by draft facets are corrected slope and draft facets formed with correction factors determined by geometric errors identified in facets of a lens structure; and    (2) system comprising an array of lenses, and an array of photovoltaic cells configured with respect to the array of lenses to convert light energy passing through the array of lenses into electricity.    DESCRIPTION OF DRAWING(S) - The figure shows cross-sectional view of lens.    Lens (100)    Glass carrier (102)    Partially transmissive layer (104)    First surface of glass carrier (106)    Second surface of glass carrier (108)