New cyclic olefin polymers (COP) with a better balance of properties t
han those of conventional optical plastics have been developed by usin
g norbornene monomers. The COP are prepared by ring-opening metathesis
polymerization of norbornene monomers followed by complete hydrogenat
ion of double bonds. The COP have practically been applied for optical
uses such as lenses, prisms and optical discs.