My sis in law had a cornea eye surgery and she was told that she can't have any pain reliever it's been 1 week since the surgery?

Eye pain. Talk to the eye md. I believe he/she meant that no topical anesthetic eye drops. I'm sure it's ok to take an oral pain reliever. Make sure you are using the proper dosing frequency of your eye medications that were prescribed at the time of the surgery. Good luck.
Speak to the surgeon. Are you certain there should be a significant level of pain after the procedure? Was it prk that was performed? Do you know why pain medication was not allowed? I think speaking to the surgeon would be best.