The chemical durability of optical glass

Chemical durability, or corrosion resistance, of optical glasses is a special problem; the chemical composition of many such glasses makes them quite vulnerable. Service problems frequently encountered include those involving weathering by atmospheric moisture and leaching during processing, e.g., polishing, or handling. The mechanisms of weathering can usefully by classified as alkaline attack, or etching, and as acid attack, or leaching. Various test methods are available; these are of varying utility.