The optical potential for nucleon- 208Pb scattering below 30 MeV is calculated microscopically as the sum of a real Hartree-Fock term and a complex correction term arising from the coupling to excited states of the target. The Skyrme effective interaction is used to generate the Hartree-Fock field, the RPA excited states and the coupling. A complex local equivalent potential is defined and used to calculate scattering and absorption cross sections. The real part of the optical potential is reasonably well described in this approach while the imaginary part is too weak. Inclusion of rearrangement processes could improve the agreement with experiment.