Sure, interchangeable lens systems like the one featured on these shades are nice, but you won't even need to use them when you have the Oakley Flak 2. 0 XL Photochromic Sunglasses. They sport photochromic lenses which automatically change tint in response to changing light conditions, which means you won't be scrambling for spare lenses when clouds roll in or clear out suddenly. Of course, the interchangeable lenses are still handy in a pinch, such as when you need to pop in clear lenses for rainy rides. Hydrophilic Unobtanium nose and temple pads get tackier when wet so your sunglasses don't slip when you're working up a sweat. Lightweight and durable Plutonite lenses block out 100% of harmful UV light while offering distortion free optics. The incredibly light O Matter frame is subtly flexible for enhanced comfort, and Oakley's patented Three Point fit eliminates painful pressure points while holding the lenses in precise optical alignment. Proposition 65 Warning for California Consumers: This product contains chemicals known to the State of California to cause cancer andor birth defects or other reproductive harm.