I did some tests with the brightness, and also switching between VGA and DVI cables, but I still feel like my eyes hurt. Its one of those things where you can't make a change and notice right away if it helped, since I literally need to get away from the computer for a bit, or close my eyes to reset the bad feeling it gives me.
I've concluded that its either the integrated graphics on the computer motherboard/CPU, or some odd setting in Windows 7. My Windows XP machine doesn't do it, and my Windows 8 machine has the same exact 2 monitors and doesn't do it either.
I swear it is the integrated graphics.
A brand new U2415 is on its way. If that doesn't fix it, I will be upgrading my video card as the next step. Anyone have any video card recommendations? Keep in mind I do ZERO gaming, and I mean zero. And the only video I watch is YouTube so it can be plain jane quality. Any cards in the $30-$100 you all recommend?