After a recent Microsoft update, my Office software packages (Word, Excel, Visio, ...) started to do some strange things. Within Office 2013, the screen output would be distorted. The ribbon was not painted properly until I mouse-over them again, or moved Office programs around. Other times the display would look corrupted and the navigation tree would not be properly rendered.
The underlying issue is discussed in KB 2768648 - Performance and display issues in Office 2013 client applications.
While the underlying issue is with the video card driver, there is a workaround until the video driver is updated.
Controlling Via Registry
Set a registry key to disable the feature Disable hardware graphics acceleration:
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Common\Graphics - REG_DWORD - DisableHardwareAcceleration Value: 0x1