A method of manufacturing plastic photochromic lenses includes obtaining a lens
by polymerizing and curing a monomer mixture. The monomer mixture includes one
of monofunctional and bifunctional methacrylic ester monomers, a trifunctional
methacrylic ester monomer and a photochromic dye. Then, radiation including ultraviolet
radiation is directed onto a surface of the lens obtained so that the radiation
activates the surface of the lens to break down macromolecular chains of the surface
of the lens. A composition including an organic silicon compound and a colloidal
metal oxide is coated onto the surface of the lens exposed to the radiation. The
composition coated is cured to obtain a hard surface film.
