You can change your display contrast by using a simple keyboard shortcut:
Ctrl + Option + Cmnd + period (or >) to increase the contrast, or
Ctrl + Option + Cmnd + comma (or <) to decrease it.
Changing the contrast – keyboard shortcut
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Interesting.
It’d be nice, if there was some form of UI to give an indication of level … and perhaps also nice with a way to set it back to default.
Good find!
See http://discussions.apple.com/thread.jspa?messageID=4576319 for how to set it back