  We consider the charge asymmetry in the differential cross section of the
process $e^+e^- \rightarrow \pi^+\pi^-$. Experimental data show large
deviations from the results of the available theoretical calculations.
Motivated by this fact, we revisit the contribution of the two photon exchange
diagrams and find the origin of discrepancy in an oversimplified account of the
pion internal structure in the theoretical calculations. We present a natural
and simple approach that accounts for the pion structure in a more consistent
way and find remarkable agreement with the experimental data.
