What is UGR?

UGR is the abbreviation of Unified Glare Rating, which means unified glare value. It is a psychological parameter that measures the subjective reaction of discomfort caused by the light emitted by the lighting device in the indoor visual environment to the human eye. Its value can be calculated using the CIE unified glare value formula according to the prescribed calculation conditions.

The range of UGR is between 10 and 30, and the values produced by most lighting systems will be within this range; a high value represents significant uncomfortable glare, while a low value represents no uncomfortable glare. Below is a comparison chart with or without glare: