Via Smoking Apples Blog.

“For night owls like myself, having a super bright display is one curse. We can never use a bright white wallpaper, and turning down the brightness only helps so much. Opening up a web page usually involves some amount of eye tear. Okay maybe I’m exaggerating, but this is a common experience, especially with the larger displays of the iMacs or perhaps even a dual 30” monitor setup.

So far the only app I’ve known to reduce brightness below the point allowed by system hardware, is ScreenShade. But the problem—which wasn’t evident at the time—was that it dims the entire screen, which isn’t the ideal way to go about things. I’ve just stumbled upon this brilliant app Blackout from BravoBug Software, and it brings a unique twist to the tale of night lighting.”