Round Bamboo Wood Sunglasses with Blue Mirrored Polarized Lenses. The Rio is an ultra-modern round lens-shaped style, but what makes it even more trendy is that the lens is made out of one piece, including the bridge. The legs are made of bamboo wood. The front is made of polycarbonate. We use outward flexible metal hinges for a flexible and comfortable fit. All GOWOOD sunglasses provide real protection with their FDA approved and CE certified category 3 high-quality lenses.