Doctor recommended GUNNAR lens technology blocks harmful blue light and 100% UV light with two different tint options; Clear (blocks 35% blue light) and Amber (blocks 65% blue light). Stylish and durable round nylon frame with hingeless design for more flexibility. Lens includes anti-glare and smudge resistant coatings. Glasses come with a premium GUNNAR Youth hard case with zipper and safety clip plus cleaning cloth. Designed and built by GUNNAR the experts in performance enhancing blue light computer and gaming glasses. Prescription Range: -5 to +5. A-fit/Standard Fit.