Photorefractive Keratectomy (PRK) was the most common laser eye surgery procedure before LASIK.
The PRK procedure involves first removing the top layer of the cornea – the epithelium and then reshaping the cornea with the Excimer Laser. The epithelium is then allowed to regenerate and this may take between 3 and 7 days. Unlike LASIK, PRK does not create a permanent flap in the deeper corneal layers.
Both PRK and LASEK are more painful than LASIK or IntraLASIK, and visual recovery can take a few days to a week, compared to only one day with LASIK.
PRK can be very uncomfortable and because of this, many practitioners advocate only performing one eye at a time.