UV Protection Category: 1-3. Lens Type: Mirror Photochromic. Quattroflex lenses are ideal for combining with Varioflex since they are lighter than regular polarised lenses. This ensures the Quattroflex effect also works perfectly in bad weather and diffused lighting conditions making the Quattroflex lens ideally suited for a wide variety of uses, from water sports to golf as well as winter sports.The hydrophobic, i.e. water-repellent, nanostructure of the lens causes water to form into beads and roll away in the blink of an eye, taking any dirt with it. This not only leaves the lens clean but instantly dry as well.Fogstop is a coating applied to the inside of the lens. It is not smooth but rough – seen through a microscope it looks quite fissured. This makes it impossible for moisture droplets to form a covering layer, i.e. to mist up the lens, impairing visibility. This could only occur if the humidity level was such that all the fissures are filled with water. But before this can happen, the stored moisture actually condenses, keeping the lens clear.