In addition, the second optical layers can be formed from polymers and copolymers such as polyesters and polycarbonates. [0092] Preferred second polymers include homopolymers of poly(methylmethacrylate) (PMMA), such as those available from Ineos Acrylics, Inc. (Wilmington, Del.), under the tradenames CP71 and CP80, or poly(ethyl methacrylate) (PEMA) that has a lower glass transition temperature th