Geerdinck, van Gheluwe, and Vissenberg investigated uncomfortable glare in office environments. They report that “disagreement exists on how to evaluate glare of non-uniform sources. This recently gained attention with the introduction of small and bright LEDs in general lighting. Earlier studies in a laboratory set-up showed that with equivalent average luminance, discomfort glare from a non-uniform stimulus seems to be greater than that of a uniform stimulus.”
In a study in a simulated office environment, the researchers determined that “In agreement with earlier work it can be concluded that point array LED luminaires provoke more discomfort glare in open plan offices than uniform sources. . . . the current studies show that luminaires with non-uniform luminance patterns and high luminance contrasts provoke more discomfort glare in open plan offices than uniform sources.”
L. Geerdinck, J. van Gheluwe, and M. Vissenberg. “Discomfort Glare Perception of Non-Uniform Light Sources in an Office Setting.” Journal of Environmental Psychology, in press.