The VZUM™ F-LENS technology is an interchangeable photochromatic lens that adapts itself to the intensity of the light present in the environment. It automatically changes colour, shielding off harmful UV rays of any sort. Their temporary transformation takes place in a short period of time, gradual and independent of any atmospheric factors. The optical strain is reduced to a minimum and the lenses remain active even on a cloudy day (1). The photochromic molecules are directly embedded in the mass of the polymer for an excellent quality and maximum resistance. The state-of-the-art photocromatic sun lenses.