A molecular theory of circular and axial birefringence and dichroism induced by circularly polarized, linearly polarized or unpolarized light in media composed either of chiral or of achiral molecules is presented. The general analytical expressions for all molecular contributions are given in terms of linear and nonlinear susceptibilities and discussed for some specific cases. The estimations of order of magnitude and comparison with other types of birefringence show that the optically induced birefringence may be noticeable in liquids and solutions by advanced laser and optoelectronic techniques.