Search Migrainous Infarction. I had one when I was 32 (53 now). It's very rare, but a migraine can cause a stroke (ie. permanent brain damage), because of impaired blood flow. It left me with a permanent scotoma ("black" hole in my fov, visible from both eyes and with both eyes open).

I was scanning the comments to see if anyone needed that information.

If the aura doesn't stop after an hour, better go to the hospital (aura means reduced blood flow). Also NEVER take triptans during an aura.