<p>It has been known that As₂S₃ glass exhibits photo-induced deformation upon linearly polarized bandgap illumination, while its mechanism remains ambiguous. To get some insight, we examine photo-induced bending (PIB) behaviors in Ag–As–S glasses. We observed a peculiar phenomenon in Ag–As–S glasses with a high Ag⁺ concentration. In the Ag⁺-free and very small Ag⁺ dissolved As–S glasses, the direction of bending can be controlled by the azimuth of the linearly polarized light. We argue that the distorted layered structure observed in covalent As₂S₃ and small Ag⁺-containing Ag–As–S glasses is a prerequisite for PIB, and a three-dimensionally extended network suppresses bending due to rectification by an ionic Ag–S bond. The exception is crystalline As₂S₃, which has a perfect layered structure, resulting in no PIB. We speculate that PIB, a type of photo-induced phenomenon, does not occur when the Ag⁺–Ag⁺ distance is shorter than the distance between the distorted layers when Ag⁺ is homogeneously distributed. We propose a model in which the microscopic structure change of the distorted layers, dependent on the linear polarization, is constrained by the presence of interlinking Ag–S bonds in large Ag⁺-containing glasses.</p>