The optical properties of chalcogenide glasses present a great scientific interest for the establishment of the general legitimacy of interaction of the optical irradiation with the amorphous solids, as well as a practical interest. The effect of lightinduced photostructural transformations in amorphous chalcogenides films have been initiated many applications of amorphous material in photonics and optoelectronics, especially as inorganic photo-resists for sub-micron technology. The optical parameters of amorphous Sb₂Se ₃ and Sb₂Se₃:Sn_x (x=0.01, 0.5, 10 at. Sn %) prepared by vacuum evaporation on glass substrates was determined from transmission spectra. The band gap was found to be E_g=1.30 eV for amorphous Sb₂Se₃ and decrease with increasing of tin concentration up to E_g=1.0 eV for Sb₂Se ₃:Sn10.0. for determination of the refractive index the approximation method proposed by Valeev was used. The maximum modifications of the refractive index under the light irradiation δn (δn=0.20) occur for the composition Sb₂Se₃:Sn0.01. That allows us to conclude that doping of amorphous Sb₂Se₃ films with small concentrations of tin initiate the photostructural transformations under the light irradiation, and make these materials suitable for registration of optical and holographic information.