Hello there, HappyCampr2002.
Here's a great Knowledge Base article that gets into troubleshooting Display issues:
Thanks for reaching out to Apple Support Communities.
YOU HAVE TO INCLUDE THINGS LIKE WHAT GRAPHIC CARD YOU USE.
Because the first suggestion is X1900, OEM 7300GT, 8800GT are all due for upgrade/replacement.
Do yourself a favor the ATI 5770 from Apple works well for us and 10.7.5.
You could also use Lion Recovery Mode / pull your hard drive and boot from a bootable clone backup (because you know about and learned to do that years ago with SuperDuper or CCC or one of the other programs).
Dust, heat, old FBDIMMs, graphic cards that literally do give up and die.