Photorefractive keratectomy, or PRK, is a refractive procedure very similar to LASIK. They both use an excimer laser, and the end results are the same. The primary difference is that PRK does not require the creation of a corneal flap.
This seemingly minor detail actually makes a big difference in one thing: the recovery time. LASIK patients generally experience a full recovery in one week, and can even swim after two weeks. PRK patients will find that their vision will gradually get better and better over several months, but the process takes time. People in certain professions may prefer PRK because it maintains a slightly higher degree of corneal integrity. For example, a boxer subjected to gloved punches to the eye and surrounding areas may prefer to have PRK. However, we recommend LASIK to the vast majority of patients.
LASIK does have a number of criteria though, including adequate corneal thickness, and no extreme flatness or steepness. Many patients who are noncandidates for LASIK are candidates for PRK though, which makes PRK an excellent LASIK alternative. As previously mentioned, the end results are the same, and most patients see 20/20 or better with either procedure.