Probing QCD Corrections to QED Effects Through Optical Experiments in Vacuum

We suggest that the QCD corrections to QED calculations may be probed through optical experiments in vacuum. Formally, the diagram for virtual $e\bar{e}$ production is identical to the one for virtual $q\bar{q}$ production. However due to confinement, or to the growth of $\alpha_s$ as $p^2$ decreases, a direct calculation of the diagram is not allowed. At large $p^2$ we consider the virtual $q\bar{q}$ production diagram, in the intermediate region we discuss the role of the contribution of quark condensates $\left$ and at the low-energy limit we consider the resonance of the $\pi^0$. We conclude that the $\pi^0$ resonance dominates. To achieve such measurements it will be necessary to significantly increase the present experimental accuracy. It would then be possible to test the existence of quark condensates and respective cut-off energy