The Executive Committee of the CIE-USNC announced the selection of a free publication to be made available to USNC members: CIE 232:2019, "Discomfort Caused by Glare from Luminaires with a Non-Uniform Source Luminance." Each national committee is entitled to select one publication per year to be made available to NC members free of charge; this year's selection was made by the EC at it's March 2025 meeting. A copy of this report is available upon request; interested members should contact the CIE-USNC.
CIE 232:2019 was selected due to the widespread interest in the topic of discomfort glare as it applies to solid-state lighting. This report reviews evidence that the Unified Glare Rating (UGR) developed in 1995 tends to underestimate the discomfort provoked by luminaires with highly non-uniform source luminance - an issue that has become particularly relevant due to new luminaire designs enabled by the introduction of LEDs in general lighting. The report evaluates several UGR correction methods, and describes a preferred method, which resolves the discrepancies between UGR and perceived glare from non-uniform light sources.