Abstract: An enhanced acrylic for use in transparencies that provides an effective barrier to airborne environmental chemical agents that are known to craze standard stretched acrylics.

Abstract: A method of manufacturing a lens for use as a part of an aircraft including the steps of fusion bonding a sheet of acrylic to a sheet of polycarbonate to form a sheet of laminate, cutting the laminate into a blank having a configuration required by the ultimate lens configuration, heating the blank and forming it around a mold to provide a three dimensional lens body of desired size and configuration having an uninterrupted circumferential edge and having an inner polycarbonate surface and an outer acrylic surface, applying a narrow strip seal to the lens body inner surface in a narrow strip portion adjacent substantially the full circumferential edge thereof in order to bond the strip seal to the lens body, shaping the circumferential edge of the lens body around substantially the full circumferential edge thereof, and providing bushings in the lens body and strip seal so the bushings are spaced around the circumferential edge as a means of securing the lens to an aircraft.