Using these Madison Cipher spare lenses is easy. Just remove the old lenses from your Madison Cipher sunglasses and pop in the new ones. When wearing them, make sure they fit snugly on your face for the best vision and protection. To keep them in good condition, clean them regularly with a soft, lint - free cloth. Avoid using harsh chemicals or abrasive materials as they can scratch the lenses. Store them in a protective case when not in use to prevent damage. And remember, they come with a limited lifetime warranty, so if you have any issues, you're covered.