  We present an analytical treatment of gravitational lensing by a Kerr black
hole in the weak deflection limit. Lightlike geodesics are expanded as a Taylor
series up to and including third-order terms in m/b and a/b, where m is the
black hole mass, a the angular momentum and b the impact parameter of the light
ray. Positions and magnifications of individual images are computed with a
perturbative analysis. At this order, the degeneracy with the translated
Schwarzschild lens is broken. The critical curve is still a circle displaced
from the black hole position in the equatorial direction and the corresponding
caustic is point-like. The degeneracy between the black hole spin and its
inclination relative to the observer is broken through the angular coordinates
of the perturbed images.
