  We present a simple prescription for the rotation of polarization produced by
a relativistically moving gravitational lens, applicable to arbitrary
deflection angle and arbitrary velocity of the lens. When geometric optics is
applicable, two independent components contribute to the total rotation of
polarization: (i) in the frame of the lens the polarization vector experiences
minimal rotation defined by the deflection angle (as measured by a set of
remote observers, or no rotation if defined in terms of parallel-propagated
tetrad); (ii) the effect of the motion of the lens on the polarization can be
taken into account exactly using special relativistic Lorentz transformation of
polarization. The effects of the gravitational lensing are thus parametrized by
the deflection angle of the null geodesics (not necessarily small) and the
motion of the lens (not necessarily with velocities much smaller than that of
light).
