I was busy programming and I didn't notice that my room went dark. I switched on the lights. Then it struck to me. People say that while reading light should be in the front.
What do you think will be a good position for the light while programming to reduce eye-strain?
P.S: Ignore the light coming from the monitor!
I've heard, and do try to follow this at home, that a light source behind the monitor is good. I've a lamp that lights up the wall behind the monitor. I think it helps since contrast between the monitor and the wall is low.
My best advice is to use a non-white background, something even sligtly grey helps, and to rest your eyes often (like closing them for a couple of minutes.) My sight is often quite blurry when I go home, while it's usually rather sharp in the morning, so it does affect you more than you think.
The light should be anywhere where you can't see it.
Also to reduce eye-strain, reduce the brightness of your monitor. In the world of professional digital imaging where everybody has properly calibrated monitors, monitors are normally set to 100 or 120cd/m2, which is considerably less bright than a typical monitor at factory settings. I have my [calibrated to 120cd/m2] monitor at 56% brightness. Also, the ambient lighting is not meant to be particularly bright either (although I'm not sure of the numbers off the top of my head).
I have a lamp pointing at the wall behind the monitor, and believe it or not, it makes the coding more pleasure
To mirror the comments already here, I also have a light above the monitor shining against the wall. It's worth noting that it works a lot better if you cannot see the light source itself (i.e. the bulb). Mine is positioned in such a way that it reflects on the wall but you cannot see the bulb inside it. It works quite nicely, and I've had it that way for a last few years ever since i first discovered the positive effect it has when it starts getting darker.
I tend to have light sources on the left and right of my monitor, since most people look more left-to-right than up-and-down. And basically, this light source is just a window during daytime. It also means that the sun is shining against the back of your monitor, thus lessening the sun glare in your screen. At night, I just use the lamp on the ceiling but it's adjusted to shine on my desk to my left and right. At home, I also have a keyboard with build-in lights for every key, which makes it easier to type in the (accidental or game-play) dark.
Also, to reduce eye-strain, I'm avoiding large blocks of white on my screen by just changing the display properties and changing the white color for windows backgrounds to a pale yellow or green.
Light in the background behind the monitor is always good, and I like to have something illuminating my desk and keyboard too!
Some of the excerpts from the relevant articles -
Turn off the overhead fluorescent lights in your office and use floor lamps that provide indirect incandescent or halogen lighting instead.
Use a desk lamp, if possible, instead of an overhead light to reduce computer eye strain.
Position your desk lamp so it doesn't shine on your computer screen or into your eyes.
Make sure overall room illumination is no more than three times brighter than the screen.
Ceiling suspended, indirect lighting. Control outside light with blinds and shades. Keep ambient light levels low and supplement with task lighting.
If using a pc, position your desk lamp away from the monitor and away from your eyes. Direct light from a lamp would only cause more glare.
Resources -
Computer Eye Strain: 10 Steps for Relief: http://www.allaboutvision.com/cvs/irritated.htm
Reduce Computer Eye Strain: http://www.eye-exercises-for-good-vision.com/reduce-computer-eye-strain.html
Visual Ergonomics in the Office: http://www.office-ergo.com/setting.htm
I prefer light from the side. Usually direct light from behind reflects somewhat on the screen and light from behind distracts. Try placing your monitor orthogonally to an open window, and you will see that natural light from the side is awesome. No reflections, and perfect, even lighting.