COUPLE OF REPLACEMENT PHOTOCHROMIC CAT. 2-4 LENSES OUTDOOR MODEL
The photochromic lenses 2-4 are special photochromatic lenses with a smoke base color able to reach category 4 during the maximum work phase. The starting color is a very light smoke that allows the correct vision even in areas with strong shadow or very low brightness, and in the phase of maximum work is able to reach category 4 with the optimal conditions of light and UV generally used for Mountaineering and Volo sports to better protect the eye at high altitudes.
As for the common photochromatic lenses also the photochromic lens 2-4 exposed to UV radiations and to sunlight in general, initiates a reversible chemical reaction that darkens the surface of the lens until reaching category 4 (when necessary). Once the irradiation of light and UV is finished, the lens gradually returns to the original color state.