JPH05341104

PURPOSE:To provide a wear resisting coat and improve weather resistance by forming the wear resisting coat including a specified fine grain inorganic material on an optical base, and forming a silicon oxide thin film having a specified refractive index thereon. CONSTITUTION:On a lens base as an optical base material, a wear resisting coat including a fine grain inorganic material of 1-300nm is formed. A silicon oxide thin film having a refractive index less than 1.470 is further formed on the wear resisting coat by regulating the vacuum of an evaporating device. The fine grain inorganic material preferably includes those obtained by mixing one or two or more kinds of antimony oxide sol, zirconium oxide sol, titanium oxide sol, tin oxide sol, tungsten oxide sol, composite sol of titanium oxide and cerium oxide, composite sol of titanium oxide and iron oxide, composite sol of tin oxide and tungsten oxide, or tin oxide sol covered with the composite sol of tin oxide and tungsten oxide. The silicon oxide thin film is a reflection preventing film or a part thereof.