  We propose an effective current operator for nucleon electromagnetic knockout
that incorporates spinor distortion and density-dependent nucleon form factors
using an effective momentum approximation. This method can be used in a
coordinate-space approach with either relativistic or nonrelativistic optical
potentials and overlap functions. We studied these effects for the
$^{16}O(\vec{e},e' \vec{p})$ reaction at Q^2 = 0.8 (GeV/c)^2. Spinor distortion
substantially enhances the left-right asymmetry while reducing the ratio
between sideways and longitudinal recoil polarization for p-shell knockout by
about 5% for modest missing momenta. We also find that the density dependence
of nucleon form factors suggested by a quark-meson coupling model reduces the
polarization ratio further. Much larger effects are obtained for the s-shell
than for p-shell. However, both effects are subject to much larger Gordon
ambiguities than comparable nonrelativistic calculations.
