You have to be out of contacts for at least two weeks before your pre-op appointment so the measurements will be accurate. It is, as others say, a life changing operation! Contacts were ruining my eyes, and my vision was 20/500, so I had it done in 2000. I gave it to my son for his college graduation gift in December - I don't know exactly what his vision was, but his contacts were -4.50. Mine were -6.5. He is going to be a police officer, and not having to deal with contacts or glasses will be a great benefit for him.
I had glare/halos horribly at night when I had contacts - no more since the surgery. Same for my son.
Please go to a very qualified surgeon - not one of those $800 "deals" that are done by high volume people. These are your eyes!
I love being able to see - it's been over 6 years, and I think about it every morning when I get up and can see the bedside table clock.