I took mine back - when I picked them up the optometrist assured me it would take some time to get used to... after about 4 weeks I was really getting annoyed with them and wasn't sure how long it should take to get used to - it had never been that long with any other changes to my glasses... luckily I did take them back as the wrong prescription had been put in!

The optometrist's office were very accomodating and have always said if I have a problem to contact them