Hi! I have noticed a line going horizontal through my entire Macbooks screen. I first noticed it with only 1 line, but in the past three days i have seen up to 5 lines across the screen, all very close to each other. It used to go away if i tilted my screen back, but now it just goes away for about 5 seconds then comes back. There is nothing else wrong with this Macbook, and i have had it since 2009! also, the line changes color to match what is on the screen, like if i have a black photo where the line touches, that part of the line will slowly turn black. What do you think is going on?