Disclosed are a method and a system that adaptively transform visual contents inputted from a network, in accordance with the visual characteristics of a terminal user. A visual characteristics descriptor that describes the information of the user visual characteristics in a predetermined format is proposed. The descriptor includes the information of the color vision deficiency type and the color vision deficiency degree. The color vision deficiency may be described in numerical degree or textual degree. The invention adaptively transforms visual contents differently in accordance with the color vision deficiency type.