A method for making an optical device includes the steps of: rubbing an orienting film so as to stretch the molecular structure thereof and so as to permit the molecular units of the molecular structure to be aligned along a first axis and to permit the orienting space between each adjacent pair of the molecular units of the molecular structure to be oriented in a direction parallel to a second axis; and forming an optical anisotropical layer on the orienting film by applying a liquid crystal film of rod-like molecules on the orienting film which orients the rod-like molecules by virtue of spatial effect of the molecular units and the orienting spaces.