  Stable massless wormholes are theoretically interesting in their own right as
well as for astrophysical applications, especially as galactic halo objects.
Therefore, the study of gravitational lensing observables for such objects is
of importance, and we do here by applying the parametric post-Newtonian method
of Keeton and Petters to massless dyonic charged wormholes of the
Einstein-Maxwell-Dilaton field theory and to the massless Ellis wormhole of the
Einstein minimally coupled scalar field theory. The paper exemplifies how the
lensing signatures of two different solutions belonging to two different
theories could be qualitatively similar from the observational point of view.
Quantitative differences appear depending on the parameter values.
Surprisingly, there appears an unexpected divergence in the correction to
differential time delay, which seems to call for a review of its original
derivation.
