When understood and used properly, the Unified Glare Rating (UGR) can provide insight into lighting visual comfort expectations. When not understood or used improperly, UGR can lead to unintended glare, unnecessarily limited luminaire selections, and overall unexpected project results. This session will dissect the UGR metric by sharing how it has evolved as a standard metric and how it is best applied as a predicter of glare for interior spaces. It will also review human factors with glare, UGR application pitfalls and demonstrate the three categorized uses of UGR in practice.