To provide an adhesive composition which shows high adhesion with a glass substrate and has excellent heat resistance, moisture resistance and moist heat resistance, an adhesive optical film comprising an adhesive layer made of the adhesive composition, which shows high adhesion between the adhesive layer and an optical film and effectively suppresses the occurrence of adhesive residue and lack of adhesive and also has excellent heat resistance, moisture resistance and moist heat resistance, and an image display device comprising the adhesive optical film, the adhesive optical film comprises an optical film 1, an adhesive layer 3 made of a water dispersible adhesive composition comprising, as raw monomers, an alkyl (meth)acrylate ester whose alkyl group has 4 to 18 carbon atoms, a carboxyl group-containing vinyl monomer, a phosphoric acid group-containing vinyl monomer, and a copolymerizable vinyl monomer which is optionally copolymerizable with the above monomers, wherein a carboxyl group concentration is from 0.05 to 1.50 mmol/g and a phosphoric acid group concentration is from 0.01 to 0.45 mmol/g in the raw monomers, an under coat layer 2 containing an oxazoline group-containing polymer, and being interposed between the optical film 1 and the adhesive layer 3, and the adhesive optical film is applied onto an image display device.