Discomfort glare caused by white LEDs having different spectral power distributions

This paper describes an experiment to investigate discomfort glare caused by white light-emitting diode (LED) lights having different spectral power distributions. It included two groups: a ‘Metamerism’ group and a ‘correlated colour temperatures (CCT)’ group. In the former group, it was found that white lights at 7000 K constructed from different blue LEDs and the same red and green LEDs gave about the same glare perception. In the latter group, there was a significant difference in glare perception between white lights having different CCTs. Finally, glare models, including unified glare rating (UGR) and the newly derived QUGR spd , and mUGR spd models, were tested using the data from the experiment. All of them gave quite accurate predictions of the data.