Laser eye surgery essentially falls into two categories: PRK, or PhotoRefractive Keratectomy, and LASIK, or laser assisted in-situ keratomileusis. These two types of laser surgery have been modified to create variations on the same theme. LASEK as opposed to LASIK is a more modern version of PRK. All these procedures are conducted with the patient fully conscious, and drops are used to dull any sensations in the eyes.

PRK is a technique whereby the surface is manipulated to eliminate the outermost corneal layer, also known as the epithelium. Removing parts of the epithelium is the first step in the process of laser eye surgery. The next step is restructuring the cornea using an excimer laser. PRK involves scraping away the surface layer of the cornea and an excimer laser is used to reshape the tissue lying underneath the surface corneal tissue. Later, the epithelial layer will grow back. The eye regenerates itself. PRK offers an option for those whose cornea is too thin to actually cut into. However, PRK has one significant disadvantage: healing is longer and punctuated with discomfort, unlike in the case of LASIK surgery. The fact that PRK does not require the creation of a corneal flap using a microkeratome blade is a significant advantage. This process does not penetrate the inner layer of the cornea, thereby dropping the risk of inner eye pressure forcing itself on a thinned corneal surface, causing it to protrude. This will further cause vision to deteriorate in the future.

LASEK, or laser assisted sub-epithelial keratomileusis, a highly developed version of PRK, uses an alcohol solution in order to soften the epithelium before getting rid of it. After the cornea is reshaped to correct vision, the epithelium is replaced. The healing process is quicker and smoother than in PRK, and the slicing of the cornea to create a flap is still avoided. EPI-LASEK is still more advanced than LASEK. It preserves the layer of epithelial tissue that has been removed in a medium called a "separator". This procedure further reduces discomfort and speeds up healing, even moreso than LASEK.

LASIK, on the other hand, uses a microkeratome metal blade to cut a flap on the corneal surface, and then an excimer laser to reshape the cornea. This is usually pain-free and vision is corrected instantly, unlike in PRK. Blurriness, though, may be expected for up to 24 hours after the surgery.

Not everyone with eye defects is the ideal candidate for laser surgery. The risks involved are many, and serious enough not to ignore. An educated choice is always the best way to proceed.