Abstract: The present invention relates to a method of manufacturing a plastic lens comprising a cured film on at least one of a pair of opposing surfaces of a plastic lens substrate. The method of manufacturing a plastic lens of the present invention comprises heating the plastic lens substrate to a temperature greater than or equal to a glass transition temperature of the substrate; coating a photocurable composition on at least one of a pair of opposing surfaces of the lens substrate following the heating; forming a cured film by irradiating the photocurable composition that has been coated on the substrate with light to cure at least a portion of the composition; and conducting a heat treatment of the plastic lens on which the cured film has been formed at a temperature, the temperature being lower than the glass transition temperature of the substrate but greater than or equal to a glass transition temperature of the cured film.

Abstract: The present invention relates to a photochromic film comprising a photochromic dye and a resin component. The photochromic film has a nanoindentation hardness of equal to or greater than 800 nm on at least one of surfaces, surface A, thereof. The present invention further relates to a method of manufacturing a photochromic lens. The method of manufacturing a photochromic lens of the present invention comprises forming a photochromic film having a nanoindentation hardness ranging from 500 to 5000 nm on an outermost surface thereof as well as having a smaller nanoindentation hardness on a surface facing a first mold than that on the outermost surface by coating a photochromic liquid comprising a photochromic dye and a curable component on one surface of the first mold for formation of one of surfaces of a lens and subjecting the photochromic liquid to curing treatment, and a photochromic lens comprising a photochromic film on a lens substrate is obtained by means of the above first mold.

Abstract: An optional element having a cured coating film on optical base material wherein the cured coating film is prepared with a coating composition comprising an organosilicon compound and modified stannic oxide-zirconium oxide composite colloidal particles which are obtained by partially or fully coating the surface of stannic oxide-zirconium oxide composite colloidal particles with tungstic oxide-stannic oxide composite colloidal particles. The formed cured coating film is excellent in hot water resistance, and light-resistance and weathering resistance are not impaired even when the antireflection film made by vepor deposition of inorganic oxides is applied on the cured coating film.

Abstract: A coating composition comprising an organosilicon compound and modified stannic oxide - zirconium oxide composite colloidal particles which are obtained by partially or fully coating the surface of stannic oxide - zirconium oxide composite colloidal particles with tungstic oxide - stannic oxide composite colloidal particles. The formed cured coating film is excellent in hot water resistance, and light-resistance and weathering resistance are not impaired even when the antireflection film made by vepor deposition of inorganic oxides is applied on the cured coating film.

Abstract: A hard coating film is disclosed which is formed by hardening a coating composition containing the following component A and/or component B and component C:Component A:an organosilicon compound or a hydrolyzate thereof, said organosilicon compound being represented by the formula (I):(R.sup.1).sub.a (R.sup.3).sub.b Si(OR.sup.2).sub.4-(a+b) (I)Component B:an organosilicon compound or a hydrolyzate thereof, said organosilicon compound being represented by the formula (II): ##STR1## Component C: fine particles of tin oxide having a particle size of 1 to 100 millimicrons and coated with fine particles of tungsten oxide.The coating film is excellent in hot water resistance and transparency and finds particularly useful application to lenses for spectacles.

Abstract: A polyurethane lens is produced by (a) adding to a monomer mixture comprising a polyisocyanate and a polythiol, a phosphoric acid ester represented by the general formula (I) ##STR1## (R.sub.1 and R.sub.2 which may be the same or different are each an alkyl group of 1-8 carbon atoms) and then (b) subjecting the monomer mixture containing the phosphoric acid ester, obtained in the step (a) to cast polymerization in a mold for plastic lens production. Said polyurethane lens has good releasability from mold, is free from color unevenness after tinting and cloudiness, and possesses high refractive index (N.sub.D) and high optical dispersion.