You know most of sunglasses today is made of resin for the sake of not so easy to be broken. One of the fabric material we use normally is nylon, it is plastic and flexible. Maybe the material of glasses would be make into nylon then make to favric. The nylon is also called poly A, it is a kind of resin that would sewn ito favric. However, as a doctor of glasses and eyes, I really know little about the ploy or resin.The function of glasses is to care your eyes, but the facric is to make into clothes to cover your body, they are totally different! Why you ask questions of glasses and fabric, were you want to recover old glasses to make fabric? It's an interesting work and maybe it would be formed into an art craft.