Burn-in cleaner -
Displays a white image on the screen to clear screen burn-in
Displays a white image on the screen to clear screen burn-in ( a ghost-like image remaining on the screen).
Also helps to check if there is burn-in on your screen by displaying any selected color on the screen.
This method is described here.
http://support.apple.com/kb/HT2807?viewlocale=en_US
