Abstract
The I.E.S. code distinct's Glare Index and Glare Limit. The G.I. is a number that should express the degree of glare, irrespective the work to be done. In the case of ten different installations for all of which the formula is valid, the G.I. has been calculated. Besides fifteen persons have judged the degree of glare of these installations by seeing. These judgments appeared to be strikingly unanimous. The results of both investigations are compared.