MacBook Pro 2011 Unibody 10.7.5 fatally crashes even after recent repair, (lines across screen, graphics glitches, freeze up)
I recently had this issue.  It turns out that Apple has a repair program for this issue at no cost that runs until Dec 31, 2016. Here is the link:
https://www.apple.com/support/macbookpro-videoissues/

I took my laptop in to the nearest Apple Store. The Genius Bar tech ran a diagnostic test to verify the issue.  They sent it to a repair location in Texas and in 3-5 days I had it back.  There is also a 90 warranty on the work.