Patent ID: 7922941

Claim:
A photochromic plastic object, constructed from a polymer plastic material, wherein at least one essentially mesoporous inorganic host structure, which has one or more organic photochromic dyes intercalated therein to form a photochromic nanocomposite material, is introduced in or applied to said polymer plastic material; the pores of the host structure in which one or more organic photochromic dye molecules are intercalated have a diameter of 1.5 to 5 nm; said object is a spectacle lens selected from the group consisting of eyeglass lenses, sunglass lenses, safety glass lenses and protective goggles, or said object is a helmet visor, and the organic photochromic dyes are dyes which darken upon exposure to light and are selected from the group consisting of: (i) 3H-naphthopyrans, 2H-naphthopyrans, and larger ring systems derived therefrom; (ii) spirooxazine dyes; and (iii) mixtures of two or more of the foregoing.