Photoshop CS6 introduced a new interface option which allows you to choose from four shades of brightness while working in the app. It was jarring at first, but once I got used to it I loved it. Still, there are times when I want to leave the new dark interface and use something a bit lighter. Adobe made it easy with a handy keyboard shortcut.
Photoshop CS6 offers interface brightness flexibility
Simply hit Shift + Function + F1 to lighten the interface, or Shift + Function + F2 to darken it.