Background
Photorefractive keratectomy (PRK) consists of the application of energy of the ultraviolet range generated by an argon fluoride (ArF) excimer laser to the anterior corneal stroma to change its curvature and, thus, to correct a refractive error. The physical process of remodeling the corneal stroma by ultraviolet (193 nm wavelength) high-energy photons is known as photoablation.
An image depicting human eye anatomy can be seen below.
Human eye anatomy.