Disclosed is a water-soluble eye drop comprising (a) at least one selected form carteolol and an acid addition salt thereof, (b) at least one acrylic polymer selected from a straight-chain type polyacrylic acid and a pharmaceutically acceptable water-soluble salt thereof, and (c) at least one selected from a water-soluble alkali metal salt and a water-soluble amine. The water-soluble eye drop of the present invention has a remarkably long duration time of drug efficacy, and is superior in intraocular pressure inhibition action and is effective for treatment of glaucoma.
