A new method of experimental determination of the local-field parameters of the light wave in uniaxial molecular media from spectral data has been suggested and realized for several tens of doped liquid crystalline and anisotropic polymeric systems. Anisotropy of the effective local-field tensor for the solute molecules has been found to be determined mainly by the matrix's anisotropic optical properties and also to depend on the specific features of the solute molecules' electronic structure but not to depend on the shape and character of the orientational order of the solute molecules.