A significant advantage of Fourier optics over classical optics is that it permits a differentiation between optical and retinal-neural causes of visual impairment. The basic methods of Fourier optics are introduced in a nonmathematical manner, as are their relationship to current clinical methods of measuring visual performance. Potential ophthalmic applications for Fourier optics in both clinical diagnosis and pre-operative ocular evaluation are discussed, and the importance of clinical measurement of visual performance at intermediate contrast states is emphasized.