Let there be light… but not glare!

We have all experienced the uncomfortable or even debilitating effects of glare. Too often we step out of a darker house into the bright outdoors or we are driving to reach the top of a hill or crest and get blinded by the full sun! Glare is a visual sensation caused by too much brightness and can be termed disability glare or discomfort glare.¹

Disability glare is when intense light sources actually reduce visibility whereas discomfort glare is when a very bright light causes annoyance or even pain². Older people are more sensitive to glare due to the changes of the eye structure that occur with age³.

Glare can occur from a direct light source such as daylight or exposure to unshielded luminous element (globe/lamp) from luminaires (light fittings) or reflected when it bounces off a high light value surface⁴. Whilst there are several factors contributing to glare such as brightness, size, configuration and position of the source as well as the brightness of the surrounding area, a number of these can be addressed through appropriate design (selection of luminaires and lighting design of spaces)⁵.

Don’t forget the office staff too – glare impacts on the ability to see the computer clearly!

References

1.       Lighting Research Centre, 2007. Light Pollution Questions and Answers. http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/glare.asp

2.       Rea, M.S. 2000. IESNA Lighting Handbook: Reference and Application, 9th edition. New York: Illuminating Engineering Society.

3.       Jaul, E., & Barron, J. 2017. Age-Related Diseases and Clinical and Public Health Implications for the 85 Years Old and Over Population. Frontiers in Public Health, 5, 335. http://doi.org/10.3389/fpubh.2017.00335.

4.       Benbow, W. 2013. Lighting and noise design in dementia care facilities.  Canadian Nursing Home. 24(3):4-11.

5.       https://cdn.brightgreen.com/files/general/How-to-Reduce-Glare-for-Comfortable-Lighting-Levels-0.pdf