  A suitable correction of the Maxwell model brings to an enlargement of the
space of solutions, allowing for the existence of solitons in vacuum. We review
the basic achievements of the theory and discuss some approximation results
based on an explicit finite-difference technique. The experiments in two
dimensions simulate travelling solitary electromagnetic waves, and show their
interaction with conductive walls. In particular, the classical dispersion,
exhibited by the passage of a photon through a small aperture, is examined.
