Debuted in 1978, Porsche Design's P´8478 aviators were the world's first to have an interchangeable lens system, an innovation that still performs well today. The extremely lightweight black and silver titanium frames have a quick-lock system that lets the wearer swap out the lenses as light conditions change. The teardrop base 6 curved lenses are made from scratch-proof, nearly unbreakable polycarbonate, and two sets are included with each pair of sunglasses.