Have you actually had an eye exam lately? I think you can now be 20/40 (maybe even worse) correctable to 20/20. Drink a lot of water, get plently of rest and don't strain your eyes (i.e. reading, computer stuff) for a few days. Then go get your eyes checked.
There are too many unknowns with PRK; use it as a last resort (that's the voice of experience speaking).