There is constantly a small section of green speckles at the bottom of my screen. It started off small, then over the next few days, it got quite larger. The only way I can really describe how it looks is "seaweed". It's almost opaque, but I can see through it to what's on my screen a tiny bit. When I plug the laptop into a monitor, the "seaweed" doesn't show up on the monitor, but still on the laptop screen. If I press down on the screen and rub across the green stuff, it moves around very slightly and spreads out a bit, so the first time I did that was the last time. I have a Lenovo B570, that started off with Windows 7, then I upgraded to Windows 8. The problem started before the upgrade.