A PSYCHOPHYSICAL MODEL OF DISCOMFORT GLARE IN BOTH OUTDOOR AND INDOOR APPLICATIONS

Discomfort glare remains a difficult to understand and quantify problem. With the introduction of LEDs in general lighting, many new luminaire types which show a light emitting surface with high local luminance contrasts and peaks are encountered. The currently known models for discomfort glare are incapable of quantifying discomfort glare perception for such extreme luminaires. We approach discomfort glare as a special case of visual discomfort and use a mathematical ratio of Gaussians model of the retinal receptive field function to estimate the level of discomfort of office and road lighting luminaires. The resulting visual discomfort glare (VDG) model quantifies discomfort glare from office luminaires with a relatively smooth luminance distribution equally well as the commonly used UGR metric. In contrast to the existing discomfort glare models, the VDG model is demonstrated to be able to quantify the discomfort glare from very inhomogeneous sources, representative for both office and road lighting luminaires.