Geek chic is back on the block, thanks to these vintage-inspired Derek Cardigan 7011 Brown Tortoiseshell sunglasses. First invented in 1947, these stylish brown acetate tortoiseshell brow-line sunglasses will match just about any outfit brilliantly. They also compliment the solid Brown lenses, which not only offer optimum protection from the sun's harmful UVA and UVB rays, but they're also polarized, to cut down on sun glare. Woo Hoo, no more squinting! The mathematical division and multiplication symbols are featured on the frames with the equal sign on the arms, so the whole world will know you're a Mathelete. The interior spring hinges and easily adjustable nose pads work over time to help make for comfortable all-day wear. Oh, you say you need prescription lenses? No worries, because we can help with that. These brown tortoiseshell sunglasses can easily be outfitted with your required prescription. Just follow the step by step instructions for entering your required prescription during the checkout process, and you're good to go. The classic yet contemporary and iconic shape and curved lines of the Derek Cardigan Brown tortoise shell sunglasses work for all face shapes -- especially yours.