Guideline Eyegear Rio Sunglasses with Freestone Brown Polarized Lens, Tortoise Rio is an exceptional proven performer with its locking hinges, high visibility temple treatments and rubber nose pads A dramatic take on the wrap design with the added advantage of Guidelines Bio Based Polymer frame Inshore Green Mirror with Brown Tint enhances color contrast and overall visual acuity These sunglasses have a Polarized Polycarbonate Lens that offers 100% UVA/UVB protection Available in three popular lens tints with VLT (visible light transmission) from 8.0% - 11.8%