Products 　CR-39 HARD RESIN 　LENS SERIES       The Advantage of CR-39 Lens 1.Low weight Lenses of hard resin have density of 1.31g/cm3,almost half of that of standard crown glass.The low weight of the lenses gives more comfort for the spectacle wearer. 2.Safety Lenese of hard resin have excellent impact resistance lens with a centre thickness of 2mm or more comply with the CEN lens-stength norm and the FDA balldrop test norm. 3.Optical quality Lenses of hard resin have very hight light transmission(Among the highest for optical plastics).The ABBE number is hight (59).CR-39 gives a sharp defined image for plastics. 4.Special Lens Treatment Monomer allow for special treatment such as rimless frames,color tinting for style or sunglass ,UV-protection and photochromic. 5.Lens Curve Stailing The temerature resistance of CR-39 monomer gives plastic lenses the strength to sustain stable curve design.   Raw material DIETHYLENE GLYCOL BIS(ALLYL,CARBONATE) Raw material manufacturer PPG industrial Ltd.& great lake Chemica