British Standards for Spectacles.

EARLIER articles have reviewed parts of the work of the British Standards Institution in the field of standardization of spectacles (Brit. J. Ophthal., 1956, 40, 611; 1959, 43, 509), but the publication of B.S. 3521, completing the series of Standards relating to spectacles, provides the opportunity for a general survey. The nine British Standards fall into two categories with some overlap. There are; first, those of direct appeal to prescribers, 2738, 3162, 3199, and 3521. These provide the criteria by which to judge the finished product, or state the language which discussion should use, or define the accuracy of the testing upon which prescribing is based. The rest are primarily the manufacturers' concern, relating as they do particularly to the. quality of materials and components. These are B.S. 3062, 3172, 3186, 3352, and 3462 and need not be studied except by those specially interested.