Ah ha!
So I went to get my eyes checked today, and ... my prescription has changed. So has my astigmatism. No wonder I'm getting headaches and things sometimes looked warped when I look at them. I had to walk around the office forever with the weird glasses to test my vision. I had problems getting a prescription that didn't distort in the third dimension. I had things jumping at me, tilting backwards, looking like they were in a long tunnel. Very weird. So we finally got it right! So as you can imagine, all of this was a nightmare to try to explain in Japanese. Luckily, one of the staff spoke English! Phew! So now I'll have new glasses on Monday and hopefully no more headaches!