Were you able to perform a Safe Boot? What you're describing could be a hardware or software issue. If you're able to do a Safe Boot, it's more likely a software issue. To perform a Safe Boot, hold the Shift key down right after you hit the power button and keep holding it down until a horizontal bar appears below the Apple on the gray screen. This will perform special diagnositics/fixes and boot the Mac with only essential kernel extensions.
The vertical/horizontal lines are, however, really suggestive of a hardware problem, like a video card defect or defect in the connection of the computer to the display.