FROM ONE EXTREME TO THE OTHER Photochromic lenses (cat. 2 to 4 - visible light transmission rate: 5% - 20%), they get darker or lighter to match changing light conditions, and polarization eliminates glare on reflective surfaces. Lenses adapt to changes in exposure and glare. Ideal for extreme visual conditions: desert, sailing, high mountains and skiing. Improved reading of relief and maximum protection thanks to polarization. Internal anti-fog coating.