The first sunglasses were "invented" 2,000 years ago. The Inuit (eskimos) created snow goggles from animal bone, leather and wood. There were small slits that allowed only the tiniest of light through. This effectively shielded the eyes from the blinding glare of sunlight reflected off the snow. Talk about innovation!
As cool as the eskimos 2,000 year old frames are, you might be looking for something a bit more stylish.