A fantastic article from LUX
The whole lighting industry needs to understand the issues and not just put on a specification UGR19 compliant.
A great article to read.
UGR stands for unified glare index. It’s a numerical way of defining how bright a luminaire appears in-situ and it goes back to the earliest editions of lighting codes for interior lighting – office lighting, in particular. In the early days of desk-top computers there was a serious problem caused by the reflections of light fittings in highly-reflective screens. This is the best-known image and was included in all editions of the lighting codes: Of course, it didn’t take long for the screen manufacturers to make the whole issue redundant by shifting to low-reflective screens. And that, we thought, was that.