The present invention relates to a polymer comprising a hyperbranched dendritic polyether backbone covalently bonded via an oxygen bridge to at least one UV absorbing chromophore characterized in that the hyperbranched dendritic polyether backbone is obtainable by a ring-opening polymerization of at least one oxetane. Such polymers are particularly useful as UV-filter substances for example in compositions for the protection of the human skin and/or hair against harmful effects of sunlight.