The present invention is concerned with a sterile aqueous ophthalmic solution comprising about 0.05% to about 0.5% (w/w) of N-(N-acetylcysteinyl-)chitosan or a pharmaceutically acceptable salt thereof in a carrier solution, wherein the N-(N-acetylcysteinyl-)chitosan has a content of free thiol groups in an amount of from 80 μmol/g polymer to 280 μmol/g polymer. The invention is also concerned with a container containing said ophthalmic solution as well as the use thereof in the prevention or treatment of dry eye syndrome or dry eye signs and/or symptoms.
