Diving goggles feature patented, exclusive Liquidskin technology. Bi-silicone technology uses two different types of silicone: a firmer portion for support structure and a softer portion for contact with your face. It is 45% softer for unparalleled comfort and 270% more elastic for a perfect fit. The advantage of glasses is optical lenses that are easy to install. In addition to negative diopters (-1 to -7), positive diopters (+1.5 to +3) are also available. Small horizontal ribs in the area around the nose absorb and redistribute the pressure exerted by the frame, resulting in increased comfort.