The way in which in-grown strain impacts the optical properties of crystals can be revealed when combined with annealing studies. During the annealing process strains may be relieved, and when they are, the intrinsic energy bands adjust to these changes. These changes are readily detected by reflection measurements. Energy changes in the intrinsic bands may also be reflected in the extrinsic optical transitions. In this paper we show how stress changes during the annealing process can be used to develop a model that explains the origin of emission lines at 3.2898 and 3.2176 eV.