The variation of the glare source luminance according to the average luminance of visual field

This study was conducted to propose a method of identifying glare sources from windows. Discomfort glare from windows of a classroom was evaluated in the experiments involving subjects, and the features that made the subjects recognize the glare sources in the windows were explored. The results of the evaluation led to the realization that the subjects regarded the patches that were causing discomfort glare as the glare sources on windows. It means that the patches having low luminance were not the causes of discomfort glare and were excluded from glare sources for the discomfort glare evaluation. There was a linear relationship between the average luminance of the visual field and the average luminance of the glare patches. The linear relationship has been expressed by a formula. The proposed formula has made it easier to identify the glare patches from windows. The approach as suggested in this study is distinctive to the others by the fact that the glare source was determined based on the average luminance of the visual field.