I was so alarmed at the deterioration of my eyesight (and I didn't put 2+2 together that it was related to the patch) that I immediately scheduled an optometrist appointment when I got back. Of course by the the time the appointment came, my vision was normal again, so I got some reading glasses and didn't think anything about it.
Then we went on a cruise and the same thing happened, only this time my daughter used a patch as well and she commented how the patch was making her vision blurry. So then I googled the side effects and that was one of the most common side effects.
Not a big deal - it clears up within a day after you take the patch off, and it's not like you are blind. But for me, everything was noticeably blurry.