  Propagation of light in nonlinear materials is here studied in the regime of
the geometrical optics. It is shown that a spherically symmetric medium at rest
with some specific dielectric properties can be used to produce an exact
analogue model for a class of space-times which includes spherically symmetric
and static black hole solutions. The optical model here presented can be a
useful tool to reproduce in laboratory the behavior of optical null geodesics
near a compact object with an observable gravitational Schwarzschild radius.
