Infrared reflection spectroscopy is used to obtain a non-destructive surface analysis of structural changes associated with the aqueous corrosion of two simulated medieval glasses. Variations in aqueous corrosion time and temperature, and differences in glass composition appear as changes in the spectroscopic fingerprint of the glass surface. Sequential removal by polishing of two different types of glass surface damage, silica rich skin formation, and pitting corrosion, could be followed by this method. Applications in conservation procedures are suggested. -- AATA