I get used to work at home in complete darkness, regardless of whether I'm currently gazing at 27' monitor or looking into 13' notebook screen.

Recently a friend of mine has told that this is quite harmful to vision - basically because of staring at something very bright without any other light sources. My question is - Does there indeed exist an experimentally proven best practice for lightning mode for, well, I guess, for all of us, office workers.


I have been programming on video displays for 40 years now. I always chose the ambient lighting, location, and screen settings so that the contrast between screen and surroundings is minimized.

Obviously that means do not put a screen in front of a bright window, and if you have a choice work in a room that has a north facing window. A dark room provides too much contrast between the screen and the surroundings which your eyes see. The light in the room should not be bright because you can't really crank up screen brightness enough to match. Somewhere between dim lighting to a sort of medium normal lighting level is good, and do adjust the screen brightness until it is comfortable to glance at the screen and the room and back again several times.

Ideally, the window in the room will be to your right or your left and will have a DISTANT view in it. You can build the habit of looking out the window every 5-10 minutes and staring at the most distant objects for 30 seconds or so. If you build this habit you will write better code because it is amazing how much you can think over the code in those 30 seconds of staring at a distant tree or building.

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    "A North facing window" - I'm assuming this doesn't apply to both hemispheres Feb 13 '14 at 21:12
  • +1 I do the same stuff, probably similar age to you. I'm quite aware also how these factors aren't an issue for 20 year old eyes. Feb 13 '14 at 21:30

Your eyes have two components involved with the actual light detection.

You have cones - these can determine color. You have rods - these can't determine color, just the presence of light.

For this discussion we are talking about rods.

They basically wear out over time (decades) and your eyes become less and less able to see. One of the ways this manifests itself is that your ability to look at objects directly in front of you is greatly diminished by a wash of glare from more peripheral vision. You have a lot more rods in your peripheral vision

Two of the most common examples of this are night driving, where on-coming headlights overload the eye and result in a lot of glare. The other is trying to work on a computer with a window behind it. The light from the window will overpower you eyes more as your rods diminish and make it hard to see the screen.

I believe that the lights on in the room won't make much of a difference. the deterioration occurs over decades. Having brights lights or windows will exacerbate the issue but not actually contribute to it much in the first place.

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    Eventually...? Was there anything else?
    – Hugo Rocha
    Feb 13 '14 at 20:29
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    fixed (removed) was going to get philosophical about bionic eyes and then eternal life in machines but changed my mind! Feb 13 '14 at 21:28
  • I never asked for this.
    – Hugo Rocha
    Feb 14 '14 at 12:49

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