NEVER HIDE Alexza NH95301/71 sunglasses. The frame material is 100% handmade acetate. It is a nylon based acetate that is hypoallergenic, also known as cellulose acetate and is made from superior quality wood pulp and cotton. This material is a lot stronger, more durable and flexible than regular plastic.The lens are made from our High Definition (HD) nylon lens. These lens are made from superlight low specific gravity nylon which are completely suitable for sports usage. The high ABBE value further enhance sporting performance by providing crystal clear clarity with optimum sharpness. To achieve maximum eye protection, our high material HD nylon lens block 85% of visible light for comfortable vision and block most of the blue light as well. It is 100% UV protection from direct harmful sunlight.