In his latest blog post, Jeff Atwood states:

We computer geeks like it dark. Really dark. Ideally, we'd be in a cave. A cave … with an internet connection.

The one thing that we can't abide is direct overhead lighting. Every time the overhead light gets turned on in this room, I feel like a Gremlin shrieking Bright light! Bright light! Oh, how it burns!

But there is a rational basis for preferring a darkened room. The light setup in a lot of common computing environments causes glare on the screen:


While a darkened room is better for viewing most types of computer displays, it has risks of its own.

This is inconsistent with my personal experience: overhead lighting is good, and if positioned so that it doesn't create glare (not that hard, really), is way superior to a dark room.

Are there any documented advantages* to working in a "cave" with some monitor backlighing ("bias lighting")?

*Advantages such as: better health, better productivity, more happiness. The article is to be read in terms of increasing productivity and looking for the perfect programming environment. I am not interested in environmental or cost savings of any kind.

  • Pseudo-answers/random discussion removed from comments. Please stick to trying to improve the question in comments, extended discussion belongs in Skeptics Chat.
    – Jamiec
    Commented Feb 1, 2016 at 15:06

1 Answer 1

  1. According to the OSHA manual on preventing strain from working with video display terminals, three elements are of concern when it comes to lighting:

    • quantity (lower lighting is better, OSHA recommends “28-50 foot candles”)
    • contrast (lower produces less strain)
    • glare (again, lower or more diffuse light is better)

    See: http://www.osha.gov/Publications/videoDisplay/videoDisplay.html

  2. The American Optometry Association has similar recommendations on their website:


    The AOA makes the point that if any of your work requires accessing other materials within your workspace, you will require a bit more light.

  3. While too much lighting can have negative effects, primarily due to glare as noted in Atwood’s quote, this does not mean that it’s best to work in complete darkness. Several studies have found that there is a lower level at which eyesight begins to be affected while using a computer. See Aaras, et al., 1998, Sugimoto, Ikeda, & Noguchi, 1999, and Wolska & Switula, 1999 for examples.

    This question was answered by an information science student as part of the monthly Slam the Boards! event:


Aaras, Arne, Gunnar Horgen, Hans-Henrik Bjørset, Ola Ro, and Magne Thoresen. "Musculoskeletal, visual and psychosocial stress in VDU operators before and after multidisciplinary ergonomic interventions." Applied Ergonomics 29, no. 5 (October 1998): 335-3554. Accessed November 9, 2011. http://www.sciencedirect.com/science/article/pii/S0003687097000793 .

American Optometry Association. "The Effects of Video Display Terminal Use on Eye Health and Vision." American Optometry Association. Accessed November 9, 2011. http://www.aoa.org/x5380.xml.

Occupational Safety and Health Administration. "Working Safely with Video Display Terminals." Occupational Safety and Health Administration. Accessed November 9, 2011. Last modified 1997.

Sugimoto, S, I. Ikeda, and Y. Noguchi. "Estimation of physiological effects of lighting by analysis of heart rate variability." Paper presented at the 24th Session of the CIE, Warsaw, June 24-30, 1999.

Wolska, A., and Switula, M. "Luminance distribution on VDT work stands and visual fatigue." Paper presented at the 24th Session of the CIE, Warsaw, June 24-30, 1999.

  • 1
    On the productivity side... how much more likely are people to nod off in low light than the ultra-bright florescent that I am forced to work in... not that I mind except for the 2 that are just inside my peripheral vision!
    – Chad
    Commented Nov 10, 2011 at 14:29
  • 1
    I can't work under flourescent lighting for very long -- my eyes begin to feel dry and I get a headache (other types of lighting, or no lighting, are fine for me). I know a few other people who get the same effects, and one of them solved his problem at work by removing the flourescent bulbs in his office and using incandescent lighting instead. Commented Nov 10, 2011 at 21:38
  • 50 footcandles is over 500 lux, that's rather bright.
    – vartec
    Commented Nov 11, 2011 at 10:10
  • @vartec My state's legislation for some work areas, including IT, demands a 900lux environment. At the end of the day, your eyes feel like they're melting away.
    – T. Sar
    Commented Nov 5, 2015 at 11:11
  • re those complaining re bright light how many lux is daylight?
    – mmmmmm
    Commented Jan 31, 2016 at 19:23

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