Fit & Design: Oversized frame style for most or a perfect XL fit 580P Polycrbonate lenses are lightweight and impact-resistant Polycarbonate and Trivex are the lightest and most durable lenses Spring hinges for a secure fit Technology: Polarized lenses protect against UV rays and filter out unwanted glare C-WALL(R) is a molecular bond which is scratch-resistant Frames made from Costa Del Mar(R) castor plant bio-based resin