The Dirac equation of the fermion in a circularly polarized electromagnetic field produces optical NMR shifts of the same order of magnitude as observed in the recent experiments of Warrenet al. By decreasing the frequency of the irradiation field the Dirac equation shows that electromagnetically induced NMR lines can be observed in the infrared or visible range in theory. A recent paper by Buckingham and Parlett [9] is criticized in detail.