The reduction of discomfort glare from windows by interesting views.

Discomfort glare is the annoyance, or temporary discomfort produced by luminance
(brightness) within the visual field that is sufficiently greater than the luminance to which the
eyes are adapted. Both small and large source glare formulae are often poor predictors of the
subjective assessment of discomfort glare and, in particular, Hopkinson's daylight glare
formula. This suggests that window glare depends on more factors than the four embodied in
the glare calculation: source luminance, source size, surround luminance and a position
index. Several studies have suggested that interest in the glare source may reduce discomfort
glare in various cases. This thesis investigated a general hypothesis that an increase in
interest in a glare source is associated with a decrease in discomfort glare.
The investigations were performed in two main parts aiming to test the effect of interest in
two cases of glare sources, a small projected screen image and a window. Indeed, a main
focus of the thesis was to explore the effect of interest in the case of a window with a
hypothesis that an increase in interest in a view is associated with a decrease in discomfort
glare from windows. However, due to difficulty in settings and revealing the observed effect
in real daylighting situations, this thesis began to see the effect of interest in the case of a
small projected screen image under a highly controlled laboratory with a hypothesis that an
increase in image interest is associated with a decrease in discomfort glare.
The findings of this thesis tended to support the general hypothesis. It has been found that an
increase in interest in a glare source is associated with a decrease in the glare discomfort,
both for a small projected screen image and a window. In addition to the interest effects,
significant effects of the glare source luminance variations (RML) and some characteristics
and contents in a glare source were also found in both cases of glare sources.