A photochromic optical article comprising an optical substrate having a photochromic layer which is formed on at least one surface thereof and contains a photochromic compound dispersed in a resin, and a thin metal oxide layer formed on said photochromic layer, characterised in that an indenonaphthopyran compound represented by following formula is used as said photochromic compound; wherein, R 26, R 27, R 28 and R 30 are respectively, hydroxyl groups, alkyl groups, trifluoromethyl groups, alkoxy groups, alkoxycarbonyl groups, carboxyl groups, alkoxymethyl groups, hydroxymethyl groups, aralkoxy groups, amino groups, substituted amino groups, cyano groups, nitro groups, halogen atoms, aralkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted heterocyclic groups having a nitrogen atom as a hetero atom and in which the nitrogen is bonded to the indenonaphtho ring, or condensed heterocyclic groups in which the heterocyclic group is condensed with an aromatic hydrocarbon ring or with an aromatic heterocyclic ring, R 29 is a dialkylamino group, or a substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom and in which the hydrogen atom is bonded to the phenyl group. Ring Q is an aliphatic hydrocarbon cyclic group, and y, y', y" and y"' are, respectively, integers of 0 to 2, said photochromic layer has a thickness of 30 to 50 μm; said thin metal oxide layer is formed by evaporation, has a thickness of 0.01 to 10 μm, is of a single-layer structure and is formed on the photochromic layer via a buffer layer of a thickness of 0.1 to 20 μm; and said buffer layer has an inorganic fine particle dispersion layer which contains colloidal particles of an inorganic compound in an amount of larger than 30% by mass but not larger than 60% by mass and is formed by dispersing said colloidal particles of an inorganic compound in a binder resin. R 26, R 27, R 28 and R 30 are respectively, hydroxyl groups, alkyl groups, trifluoromethyl groups, alkoxy groups, alkoxycarbonyl groups, carboxyl groups, alkoxymethyl groups, hydroxymethyl groups, aralkoxy groups, amino groups, substituted amino groups, cyano groups, nitro groups, halogen atoms, aralkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted heterocyclic groups having a nitrogen atom as a hetero atom and in which the nitrogen is bonded to the indenonaphtho ring, or condensed heterocyclic groups in which the heterocyclic group is condensed with an aromatic hydrocarbon ring or with an aromatic heterocyclic ring, R 29 is a dialkylamino group, or a substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom and in which the hydrogen atom is bonded to the phenyl group. Ring Q is an aliphatic hydrocarbon cyclic group, and y, y', y" and y"' are, respectively, integers of 0 to 2, said photochromic layer has a thickness of 30 to 50 μm; said thin metal oxide layer is formed by evaporation, has a thickness of 0.01 to 10 μm, is of a single-layer structure and is formed on the photochromic layer via a buffer layer of a thickness of 0.1 to 20 μm; and said buffer layer has an inorganic fine particle dispersion layer which contains colloidal particles of an inorganic compound in an amount of larger than 30% by mass but not larger than 60% by mass and is formed by dispersing said colloidal particles of an inorganic compound in a binder resin.