Using your Westcraft sunglasses is a breeze. To change the lenses, just use the V - latch mechanism. Push it gently to unlock the lens and remove it, then insert the new one and lock it back in place. When you need extra protection from wind, dust, or sunlight, attach the side shields. It's easy to do; just clip them on. For daily use, make sure to clean the lenses regularly. You can use a microfiber cloth to wipe away dirt and fingerprints. Avoid using harsh chemicals or abrasive materials as they can damage the hydrophobic and oleophobic coating on the lenses. When you're not using the sunglasses, store them in the provided case to prevent scratches. Also, if you're using the photochromic lenses, remember that they'll adjust to different light conditions, but extreme temperatures might affect their performance a bit. Enjoy your sports with these high - quality sunglasses!