Screen bar fading?

Just tonight my mac book pro (bought in the summer of 2009, runs osx, taken care of and running well) started a strange behavior.

Every few minuets the screen will bar fade (by vertical rows one pixel across) in to inverse colors then turn a milky purple/white color before snapping back to normal. the whole event takes about 3 to 5 seconds.

What is this? Is my dear computer on the fritz or is it an easily fixed problem.

edit:it also dosent show up with screen capture

the fact that it doesn't show on the screen capture points to either the cable to the screen or the screen itself.

You could double check that by plugging it into an external monitor and seeing if it happen on that, which I don't think it would.

So to fix this you will need to take it to an Apple Service Centre. Often the screen replacement costs are more than the computer is worth so be sure to get a quote first.