Using your Eastcraft sunglasses is a breeze. To change the lenses, just use the V - latch mechanism. Simply unlock it, take out the old lens, and put in the new one. If you want extra protection from wind or debris, you can attach the side shields. When you're done with them, just remove them easily. As for maintenance, since the lenses have a hydrophobic and oleophobic treatment, you can gently wipe off water, dirt, and oil with a soft, clean cloth. Avoid using rough materials that could scratch the lenses. Also, store your sunglasses in a protective case when not in use to prevent any damage. If you're using the photochromic lenses, they'll adjust to the light conditions automatically, but keep in mind that extreme temperatures might affect their performance a bit.