Using these Shinobi sunglasses is easy. When you want to change the lens, slide back the two buttons on each temple, then squeeze the middle of the nose bridge. After swapping the lens, just snap it back in place, even when you're on the go. Make sure to clean the lenses with a microfiber cloth from the microbag that comes with the sunglasses to avoid scratches. When not in use, store them in the hard case to protect them from damage. You can try different nose pieces to find the most comfortable fit for your face. And remember, these sunglasses are designed to fit well with Sweet Protection's helmets, so you can use them together for the best experience.