Try on the RB4640 at your local EyeCare Associates location. These crystal designer sunglasses from Ray-Ban Sun are perfect for enjoying time outdoors and catching some sun. Made from nylon, these sunglasses feature a design and can help you see clearly with prescription lenses. At EyeCare Associates, we can build a complete pair of Ray-Ban Sun RB4640 just for you, with custom lenses designed for your vision needs.