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

 Image Courtesy of  Trilux

Image Courtesy of Trilux

 Image Courtesy of  glarimy

Image Courtesy of glarimy

 
KnowledgeAmy Bosnar