I prefer light backgrounds, for one simple reason. Less eye strain.
If the majority of the screen is light, my pupils contract, which results in less eye strain to keep everything in focus. I can use smaller fonts & maintain readability. I used to love the Zenburn color scheme, but that just doesn't work as well for me anymore.
Note - I'm not talking black on white. I'm talking dark grey (ebebeb) on light grey (0f0f0f).
Your pupils contract because you are being overwhelmed be the amount of light coming out of your monitor. This doesn't sound so relaxing to me ;)
On the other hand, you could be myopic and under-corrected - and so suffer more when the pupils are relaxed (similar to the Night Myopia effect).
I do find it almost impossible to use dark background IDEs (such as XCode and Eclipse), because of the other GUI elements cluttering the screen (which are usually light). And this causes a lot of eye strain, because the amount of incoming light is still huge, while most of the screen is dark, relaxing the pupils and burning the retina.
Since most of my time I'm on Emacs or the terminal, I'm cool. Switching to a browser still hurts - one more incentive not to look at Hacker News while working ;)
> On the other hand, you could be myopic and under-corrected - and so suffer more when the pupils are relaxed (similar to the Night Myopia effect).
This is really interesting. I am severely myopic and have always preferred a black background.
However, last week I had cataract surgery and now with a +27.5D (!!) IOL implant in my right eye - the only eye I have, I'm not so nearsighted as I used to be (20/80 now instead of 20/200), but I am still experiencing eye strain when looking at the computer for any length of time. After switching my editor to a white background, things got a lot easier to see.
Mind you, I am only a few days post-surgery and I haven't yet gotten new glasses. I was also having a lot of issues with colorblindness and contrast sensitivity, as well as a lot of "double" vision (which was more accurately "I see 8 of those things" vision). These are now resolved, as well. All of those will factor into the equation a great deal, I'm sure, but I do find that after the cataract surgery, the light background makes for less eye strain.
I switched color schemes from "Blackboard" to "Dawn" but my Blackboard theme may have been modified a bit. I've been using it for so long, I can't remember. It almost seemed as though there were too much contrast with the dark background.
I'm still not at a point where I can use the computer for more than about an hour at a stretch. It's amazing how mentally and physically taxing adjusting to better vision can be.
Not myopic, but I do have some eye problems that limit the correction I can get. This may make me in the minority, but it also means that dark background defaults are not a positive experience for me. Text on light backgrounds is is crisp, while dark backgrounds looks like it's been badly anti-aliased.
With regards to brightness of the monitors, I keep it reasonable - about 25% of what the monitors could do.
When I have no choice, I also tone down the brighness to ridiculous low levels. On some monitors, even 0% is too bright (hint: change the contrast then, some monitors will dim the backlight some more).
I am not a doctor, so I am mostly speaking from experience.
My eyesight without glasses is bad enough (nowadays) that I can't do a fair comparison of uncorrected vision between dark and light (can't read anything either way), but letters on dark background get significantly more blurred than with a light background. The overall room lighting level also seem to play a large role. Hence, pupil size.
My guess is that not only myopic individuals, but people with any visual problems due to their corneal shape. Also LASIK patients with large pupils (but that's to be expected).
Again, not a doctor. I am hoping some doctor will step in and comment :)
Really? I found exactly the opposite. I moved from white backgrounds to a dark theme (emacs color-theme's "gnome2", basically #f5deb3 on #2f4f4f, not unlike zenburn) a year ago and found my eyes were much more relaxed after a bunch of coding.
I actually find looking at white-backgrounded web sites (like HN) to be fatiguing these days.
FWIW, I also find black backgrounds straining. I usually have to hit dark sites with readability to read them comfortably. Perhaps it's a matter of what your eyes are used to?
It's probably at least partly a matter of how the rest of your room is lit. Your sight is sharpest when your pupils are small, so a bright monitor in a bright room will work best for many people.
However, if you're looking at a dark monitor in a bright room, or at a bright monitor in a dark room, your pupils may be too large for the amount of light that reaches them to be entirely comfortable, which causes squinting and eyestrain.
A dark monitor in a dark room won't have that problem, but you may still be dealing with some increased blurriness because of your enlarged pupils, which may bother you depending on how good your eyesight is.
To be clear, a true black background is awful, I agree. Some sites think things like white/yellow on #000000 is a good idea, and it's just a terrible readability disaster. But the "DarkSlateGray" background of gnome2 is entirely different, IMHO. Give it a shot for a few days and see what you think.
I disagree. A black background on a backlit screen is less eyestrain for the same reason that a white background on printed paper is. In both cases, the significant information is on while the background is off.
Reading black on white from a backlit screen is akin to reading the wattage information from a glowing lightbulb. It hurts.
Totally the opposite for me. In the dark days of coding on Windows, I used to invert the entire screen's gamma ramp just to have white text on dark background. I found that switching back to black on white caused my eyes to squint due to the excessive brightness.
I've often wondered why computers in general still persist with black text on a white background. I'm convinced in 50 years time there will be legions of people with eye problems that could have been avoided by just inverting colours on active displays.
For this reason I only like ePubs too as you can invert the colours easily when reading on a tablet.
Pardon? I thought that Windows was one of the first systems to deviate from the "green/amber-on-black" standard terminals that ruled those bygone days.
I also prefer light backgrounds - for example the KDE konsole color scheme (light colors with black letters, a different background color automatically assigned for each tab).
Websites with white-on-black cause afterimages which persist for several seconds and are really distracting / tiring.
The combination I use -- light green (#88FF88) on dark blue (#000060) -- is very easy to focus on. In particular, having roughly the same amount of blue in the foreground and background makes blue, which is the color most subject to chromatic aberration, irrelevant for focusing.
You need some external source of light somewhere behind your monitor to prevent your pupils from dilating (bias lighting). Adjust screen luminosity so that the screen isn't your reference light source.
I've done that in the past, and it has made no difference. Even in a fully lit room (without reflections on the screens, etc), dark backgrounds are not as comfortable as light backgrounds.
[EDIT] TO clarify a bit more - I use 2x 24" monitors at the recommended distance (arms length). This means that for better or worse, most of my field of view will be taken up by the monitors, and so most of the light that hits my eyes will always be from my monitors.
If the majority of the screen is light, my pupils contract, which results in less eye strain to keep everything in focus. I can use smaller fonts & maintain readability. I used to love the Zenburn color scheme, but that just doesn't work as well for me anymore.
Note - I'm not talking black on white. I'm talking dark grey (ebebeb) on light grey (0f0f0f).