Abstract
The author, et al. made quantitative analysis of the loss caused by glare in the luminance required for identification of faces by fixing eyes on the fact that the illuminance required for the identification of persons varies depending upon the value of threshold increment (TI) studied by Caminada and van Bommel. We could obtain the following results from the experiment we conducted for the above-mentioned quantitative analysis: (1) The luminance (illuminance) required for identification of faces is dependent upon the sum of “equivalent background luminance + equivalent veiling luminance due to glare light.” (2) Reduction of the glare (equivalent veiling luminance) caused by luminaire can minimize the luminance (illuminance) required for face identification.