  The problem of the passage of light through the mouth of a zero-mass wormhole
and the possibility of observing the objects from another asymptotically flat
space-time through the mouth of a wormhole are considered. It is shown that an
individual star can have several images and the fact that the image of a flat
Lambertian screen has a complex brightness distribution for an observer located
on the opposite side of the throat. Images of two such screens visible inside
the silhouette of a massless wormhole and the distribution of radiation
intensity in their images are constructed.
