"Made of acetate, the frame is embedded with a magnet to hold up the clip-on. Features: A pair of glasses designed for multiple uses to switch between optical glasses and sunglasses in just a snap. The lenses can also be made into anti-blue light lenses. Note: This type of product is not designed for lenses with high powers, i.e.: +400/-600 or above. For a comfortable wearing experience, high powers need to be matched with higher indices."