Comparison of Glare Sensation from the Light Sources in the Central Vision and the Peripheral Vision

Reduction of discomfort glare from a lighting installation is one of important factors for comfortable lighting. In a practical room, there are several light sources located at various positions. If an occupant look around room, he will see the light sources in both central and peripheral vision. Therefore it is important to establish criteria of discomfort glare effect for two or more sources in both central and peripheral positions. For the discussion on the criteria, the difference of the glare effects between central and peripheral visions needs to be clarified. However, the experiments in former studies are not sufficient for this purpose. Authours conducted an experimental study of subjective appraisal regarding the comparison of glare sensation from the light sources in the central vision and peripheral vision. Authours compared glare of light source in the central vision with each light source in the peripheral vision of upper side, right side and lower side location. The results are as follows: (1) Both source positions have similar slope in the equal-glare curve showing the relationship between source and background luminance. (2) As far as the glare effects from solid angle of a source, peripheral vision of right side and lower side source positions is similar to central vision, but peripheral vision of upper side source position is not similar. (3) The results regarding the peripheral vision of upper side source position, show some similarities to the study by Hopkinson and Bodmann.