An induced optical anisotropy is observed as a result of interaction of a high-power CW Ar+ laser beam, with silver-ion-exchanged glasses. We have shown that the absorption of the beam by the thin layer of Ag+ produces a temperature gradient resulting in a radial stress on the surface of the sample. The induced anisotropy makes the sample behave as a thin uniaxial optical medium with axis along the direction of the beam propagation. For the polarized light, the induced anisotropy restricts the application of micro-lenses, which are made by this method. The average refraction index of the interaction area is measured.