It isn't. I guess it depends on what you mean by expensive. Considering the benefits you stand to gain from enjoying life much less dependent on glasses or contacts; and the savings from not having to buy glasses, contacts, etc., many people consider prk a very good value. Most of my patients are thrilled with their new vision and think the surgery was well worth the money they spent.
Depends. This depends on the level of refractive error which was treated. Your uncorrected vision will likely be better than prior to surgery within 2-3 days (after the cornea has healed and the contact lens is removed) unless you had only a mild prescription before. The vision will then continue to clear over the next few weeks as corneal inflammation subsides with steroid use.
Pretty quickly. Vision returns rapidly in most cases no matter how laser correction is done. Prk using chemical or mechanical removal of the corneal surface usually takes 5-7 days to completely recover, typically with the assistance of a bandage contact lens! Recovery from lasik, whether done with a mechanical microkeratome (flap maker) or a femtosecond laser, is much quicker, usually by the next day!
A number of things. Refractive error that is not amenable to lasik, complete understanding the of results and limitations of the surgery, healthy eyes. Discuss this with your eye surgeon.
2-4 weeks. Usually there is an improvement in the first week, then some blurriness with further healing and then more improvement to the best vision in the next few weeks.
Get the one. The doctor recommends. Both are safe. If the doctor is leaving the decision to you, get another opinion.