  We discuss radiative corrections to an atomic two-level system subject to an
intense driving laser field. It is shown that the Lamb shift of the
laser-dressed states, which are the natural state basis of the combined
atom-laser system, cannot be explained in terms of the Lamb shift received by
the atomic bare states which is usually observed in spectroscopic experiments.
In the final part, we propose an experimental scheme to measure these
corrections based on the incoherent resonance fluorescence spectrum of the
driven atom.
