I have light on dark design on my weblog since I started it and I've never seen it on a LCD screen yet :) I have a very old 14" CRT monitor, so LCD's not the point ;)
I've always loved that color scheme... I prefer dark colors to light :) And IMO it looks very ellegant :)

When studying design in the 80s we learnt that white or light text on a dark background provided more contrast for the text and was easier to read.

Your eyes are not asaulted by a huge screen of bright white with the black text lost in the brightness.

This is why my sites are light on dark.

PS check out my Creative Object World (cow)

I think it's mostly a matter of style. A couple of years ago drop shadows became THE attribute to have on your page. Shadows work best on light backgrounds so a lot of sites were designed that way. I think that the light on dark thing is a counter movement to that. Trends change and we have moved past glass surfaces and reflections towards glow effects and subtle shadings, which works better with dark backgrounds.

Another theory is that we've started seeing web services with a "Web 2.0" look, like Flickr and Del.iciou.us. People probably want their blogs to look more intimate than a web service so they could be moving away from that look. Maybe we are seeing a division between the personal and the corporate web?

Like most things, it is probably a little of everything.

Some people simply like the look, and have always been doing light on dark, nothing new for them.

There is certainly something to be said for breaking the Web2.0 mold. Personally, I was getting very tired of seeing the same old designs. Corporate America seems more willing to use light on dark too, perhaps as a way to make themselves stand out from the crowd.

Another reason may have to do with a change in work patterns, as Johnathan Snook noted he was looking at his designs in the evening when monitors are better able combat light conditions related to light on dark designs.

"Are light on dark designs more susceptible to lighting conditions? Seems reasonable enough. Your monitor will be pumping out less light to show whatever is on the screen. With a white background, the screen floods you with light. As a result, it's more capable of competing with high light situations." -- Jonathan Snook

And off course, light on dark is easier on the eyes.

Whatever the reasons, I'm happy to see the trend, long may it continue.

It's the additive color model of the screen that makes light on dark visually pleasant. Colors on screen are created by the transmission of light vs. reflection of light on the printed page. The lower level of intensity may simply be more comfortable. And, most of us like to sleep in the dark because it eliminates a source of distraction.

light on dark looks good and cool, but reading the text is difficult and strains the eye

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