Disclosed is a transparent polymeric diffusion film exhibiting at least 50% transmissivity containing a thermoplastic polymeric material with internal microvoids and containing a plurality of complex lenses on a surface thereof. Such films are useful for diffusing light when it is desired to provide...http://www.google.ca/patents/US6890642?utm_source=gb-gplus-sharePatent US6890642 - Surface formed lenses on voided polymer light diffuser
