Monie I have tried both. I have a Dell 21" widescreen with an LED backlight, and an older 19" Dell 4:3 display with a CCFL backlight. Both cause identical issues. I have not tried a CRT monitor, since I don't have one but if i can come across one it would be an interesting test
I ordered the USB external video card for $49 off Amazon, it will be here monday. I know it will be a "low quality" card, but quality of image doesn't seem to be an issue since folks in the Intel thread have mentioned that using the standard VGA driver solved their eye strain, and that's certainly far from high quality
On Monday I will also try booting the laptop in Safe Mode to see if I can force VGA graphics, if I can do that and don't get eye strain that will strengthen the case for it being the graphics driver even more.