A quark model calculation of the processes γγ → π + π − and γγ → π 0 π 0 is performed. At tree level, only charged pions couple to the initial state photons and neutral pions are not expected in the final state. However, a small but significant γγ → π 0 π 0 cross section is observed. We demonstrate that this may be accounted for by a rotation in isospin space induced by final state interactions. The resulting π + π − cross section is in good agreement with experiment while the π 0 π 0 cross section is in qualitative agreement with the data.