  This paper reviews a phenomenological approach to the gravitational lensing
by exotic objects such as the Ellis wormhole lens, where exotic lens objects
may follow a non-standard form of the equation of state or may obey a modified
gravity theory. A gravitational lens model is proposed in the inverse powers of
the distance, such that the Schwarzschild lens and exotic lenses can be
described in a unified manner as a one parameter family. As observational
implications, the magnification, shear, photo-centroid motion and time delay in
this lens model are discussed.
