  In this letter we estimate the contribution of the double diffractive
processes for the diphoton production in $pp$ collisions at the Large Hadron
Collider (LHC). The acceptance of the central and forward LHC detectors is
taken into account and predictions for the invariant mass, rapidity and,
transverse momentum distributions are presented. A comparison with the
predictions for the Light -- by -- Light (LbL) scattering and exclusive
diphoton production is performed. We demonstrate that the events associated to
double diffractive processes can be separated and its study can be used to
constrain the behavior of the diffractive parton distribution functions.
