My first pass didn't take. The second time around is a LOT more painful. They have to peel your half-healed eye flap back again, and man ... like being stabbed in the eyes for day, and got to keep yourself lying on your back for a week.
Point being, when I got the "bandage contacts" out, I was in Toronto at a conference. My eyesight was bad but I thought the bandages were just causing it, because they were "itchy". It got LOTS worse when they came out, and I couldn't even read the street signs downtown without looking at them at an angle. That was "fun".
Thankfully the second time worked, otherwise I'd be half blind right now. You get two, and that's all.