Last night I was installing a new web browser w/ great difficulty. After several minutes, I realized I was not misreading the instructions, rather, I couldn't see them!
Turns out I had an ocular migraine.

This was the fourth such occurrence ever for me. No pain, but weird & a little scary!
Here is a spot on description of my experience:

http://www.allaboutvision.com/condit...r-migraine.htm

Anyone else other have this?