For our second cruise (before I realized the Bonine situation) I did buy a patch and I used it for three days, changed it out and then after the fourth day, I started having a lot of trouble focusing on things close up. I was having a hard time reading my book or menus. I was squinting and holding it far away from me - the whole nine (and no, it wasn't on my fingers, I made sure to be extremely careful of touching my eyes after application). Our final day was in CC and I realized when we got back on board, my patch had fallen off. I didn't put another one on, but I was fine.