Using conductive materials, Reynard Corp. creates custom optical heated windows for keeping imaging planes or optical instrumentation windows free of moisture and fog. Available types include solid indium tin oxide, lines and grids. Customized or standard patterns are offered with linewidths down to 10 μm. The windows can be customized to achieve high transmission and/or matched impedance, and the substrate size, shape and type also can be customized. Bus bars added to the edge of the optics provide solder points to attach electrical leads. Antireflection coatings can be added to one or two sides of the optic to enhance transmission and to provide an extra layer of protection for the conductive surface.