Home / Support / Light Lab / Unified Glare Rating

Unified Glare Rating

Assessing glare with UGR

Glare might seem like a subjective term, but it is actually calculated using a precise formula. Essentially, this formula measures the luminance of a lamp divided by the background of visible luminance from the room. This number is called the Unified Glare Rating, or UGR, and it ranges from 5 to 40. The lower the number, the better. For example, a low UGR of 10 means the glare is so discreet it will go unnoticed, while UGR of 30 will definitely cause distraction.  

Source: Owen Ransen, author of "Candelas, Lumens and Lux"

Glare in the workplace

In office applications, visual comfort is critical. This is partially achieved by minimising direct glare and reflected glare.  Just like the name implies, reflected glare is excessive luminance reflected from objects or surfaces within view.  This includes reflections from interior surfaces and from the lights themselves. Proper luminaire positioning and advanced optics can reduce glare. Our LEDchroic™ technology greatly minimises glare, as does our high transmission diffuser found in our LED flat panels.  

Browse low glare products:

Glare's effect

  • Visually distracting
  • Psychologically disconcerting
  • Fatigues the eyes
  • Lowers ability to see detail

Unfamiliar with a term? Look it up!

Lighting Glossary


Upcoming Events


EuroShop 2017

Aurora will be exhibiting its new Smart retail display lighting at EuroS...

Aurora Lighting Inc. | 12035 34th St North | Suite 2  | St Petersburg FL 33716 | USA

TEL: +1 (727) 524 4270 | FAX: +1 (727) 290-3914

© 1999 - 2016 auroralighting.com


Select Location & Language

Aurora Lighting is a global organization serving markets around the world. Please select your region, or click below to visit our Global site to view our 2,500 products: