Glasses of (GeS2)(x)-(SbSI)(1-x) composition are promising precursors for making optically active transparent glass-ceramics with SbSI as the ferroelectric phase. We report the composition dependence of optical transmission of this glass series with x=0.1-0.5 and correlate it with the structure as determined by Raman spectroscopy. A short-range structural model is proposed on the basis of experiment results.