When I was getting the vision tests done, I had a panic attack at the same time. I felt out of control because of losing my vision, and the whole experience. Maybe it didn't cause it, but it definitely could have made it worse. I find if things feel 'weird' I can handle it as long as I'm not in a vulnerable position, and during the vision test I was feeling very vulnerable (weird, I know). Probably because it was new and I wasn't sure what would happen. One thing you could do is ask your t if that could have helped cause your reaction. She would have a better idea. Good luck!! Keep us posted on how it goes!
xo
IJ