We illuminate the importance of a self-consistent many-body treatment in
calculations of vacuum polarization corrections to the energies of atomic
orbitals in many-electron atoms. Including vacuum polarization in the atomic
Hamiltonian causes a substantial re-adjustment (relaxation) of the
electrostatic self-consistent field. The induced change in the electrostatic
energies is substantial for states with the orbital angular momentum l &;gt;
0. For such orbitals, the relaxation mechanism determines the sign and even
the order of magnitude of the total vacuum polarization correction. This
relaxation mechanism is illustrated with numerical results for the Cs atom