Assessing glare. Part 1: Comparing uniform and non-uniform LED luminaires

This study investigated the discomfort glare caused by LED luminaires. It included three different LED luminaire structures, under two background luminances, seen at two different angles above the line of sight. Observers scaled glare using a seven-category scale. The results showed that a darker background or a smaller angle led to more discomfort glare and a non-uniform luminaire produced more glare than a uniform one. Furthermore, Unified Glare Rating was tested using the data. It performed reasonably well, but there is still room to improve the predictions for non-uniform LED luminaires.