Lost a bunch of weight quick and my vision basically reversed. Couldn't see close up and didn't need glasses/contacts for far away. When it settled out after 3 or 4 months, I was back to near sighted but my prescription wasn't as strong (went from -2.50 to -1.75).

It wasn't very fun and pretty scary. I had issues with my hearing as well, but they cleared up as well when my sugar levels improved.