Lens Type: Mirror PhotochromicThe hydrophobic| i.ewater-repellent| nanostructure of the lens causes water to form into beads and roll away in the blink of an eye| taking any dirt with itThis not only leaves the lens clean but instantly dry as well.Fogstop is a coating applied to the inside of the lensIt is not smooth but rough – seen through a microscope it looks quite fissuredThis makes it impossible for moisture droplets to form a covering layer| i.eto mist up the lens| impairing visibilityThis could only occur if the humidity level was such that all the fissures are filled with waterBut before this can happen| the stored moisture actually condenses| keeping the lens clear