simultaneously filtering both uvc and uvb wavelengths of ultraviolet light with optical filters placed between the uv lamp and the substrate fig1 a depicts a cross sectional view of a transparent co polymer disc 101 that is cut from a section of a colored co polymer rod as shown in fig1 b a depression is introduced into a surface of disc 101 by any suitable means including but not limited to milling in fig1 c the depression is filled with co monomers or uncured co polymers at least one colorant titanium dioxide and optionally initiators crosslinkers and the like which are polymerized to form an opaque colored co polymer 102 that has a color different than disc 101 an optical zone is then formed in portions of the co polymer 102 and the underlying disc 101 the zone is formed using any suitable process including but not limited to milling as shown in fig1 d this zone is then filled with co monomers or uncured co polymers and optionally initiators crosslinkers and the like which are polymerized to form a clear co polymer 103 as shown in fig1 e the resulting disc has a distinguishable appearance depending upon whether it is viewed from above or below note that the co polymers of 101 102 and.