This International Standard gives rules for the specification of raw optical glass. It serves as a complement to ISO 10110, which provides rules specifying finished optical elements. Since raw optical glass may be quite different in shape and size from the optical elements, its specification also differs from that of optical elements. This International Standard provides guidelines for the essential specification characteristics of raw optical glass in order to improve communication between glass suppliers and optical element manufacturers. For specific applications (e.g. lasers, the infrared spectral range), specifications based on this International Standard will have to be supplemented. NOTE Additional information on how to translate optical element specifications into raw optical glass specifications is given in Annex A.