Work has been performed to investigate the effect of distilled water on the optical properties and surface degradation of the glass known as ZBLAN, that could be employed as an optical fiber. Employing spectral techniques through the use of optical spectra, exposure of this material to an aqueous environment was found to cause weakening of the glass structure and a loss in signal transmission of the material. Also using methods normally applied in the corrosion of metals and alloys, like weight loss, our data has revealed that fluoride glass containing significant levels of Zr and Ba were highly unstable in the presence of water, produced a corrosion potential, and may possibly under go electrochemical rather than chemical dissolution, which in turn allowed formation of enriched Zr and Ba surface films. Presently the exact mechanism of degradation is unclear. This instability and degradation, showed an important deterioration in the optical properties of the glass, and brings into question the selection of Zr-Ba glass as optical fiber material or its use in electronic circuits where humidity may exist.