otis hang10OTIS: We only make premium eyewear with high quality, optically – correct, mineral glass lenses. That´s it. Mineral Glass is created from natural elements like sand and soda ash. It’s endlessly recyclable and harmless to humans and animals alike. In addition, its optical clarity, high resistance to scratching and lack of distortion make it the world’s best lens material. It really does have to be Mineral Glass.