The transparency of SbSeGe glasses in the IR region makes them attractive candidates for low transmission loss applications. The samples of Sb10Se90-xGex (x = 0, 19, 21, 23, 25, 27) glasses have been prepared by melt quench technique. The thin films of these glasses have been deposited by vacuum evaporation technique. The optical study of thin films has been carried out. The refractive index, oscillator parameters, optical band gap and dielectric parameters have been calculated from optical measurements. The optical study reveals that the variation in the density of localized defect states on Ge addition affects the optical parameters of the system. The variation in concentration of localized defect states has been interpreted in terms of the change in structural network of the system. (C) 2012 Elsevier B.V. All rights reserved.