The Difference Between the Three Generations of Laser Eye Correction

Laser Eye Correction 1

PRK, LASIK and SMILE are different laser eye correction procedures that correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. The most significant differences between PRK, LASIK and SMILE are in the procedure, the initial discomfort and the speed of visual recovery.



Photorefractive keratectomy or PRK is considered the 1st generation of laser eye correction. The technique is characterized by surface ablation surgery. There are four main steps to this treatment:

  1. A diluted alcohol solution is applied to the cornea to dissolve the epithelial layer.
  2. The epithelial layer is then removed or moved to the side using a manual instrument.
  3. An excimer laser sculpts the corneal tissue within a matter of seconds to correct the visual defect.
  4. Finally, a protective bandage lens is placed over the eye until the epithelium grows back within a few hours.

Although there are other well-established laser vision correction techniques (as outlined below), PRK is well-accepted today as an economical solution.



Laser-assisted in situ keratomileusis or LASIK introduced the 2nd generation of laser eye correction. There are five main steps to this procedure:

  1. Flap creation – The eye is anaesthetized with special drops. Femtosecond laser pulses are used to create a flap on the surface of the cornea.
  2. The patient is then conveniently moved from the femtosecond laser to the excimer laser.
  3. The prepared flap is folded back like the page of a book, exposing the inner corneal tissue to be treated.
  4. The excimer laser removes the corneal tissue point by point within a few seconds, thereby correcting the visual defect.
  5. Afterward, the flap is returned to its original position, protecting the eye much like a natural bandage.

Excellent results are achieved with this flap surgery technique. Visual recovery is quick and patients rarely experience flap related effects following surgery.



Small incision lenticule extraction, or SMILE for short, is firmly established as the 3rd generation of laser eye correction beyond PRK and LASIK. There are three main steps to the SMILE procedure:

  1. A thin lenticule and small incision are created inside the intact cornea.
  2. The lenticule is removed through the incision with minimal disruption to the corneal biomechanics.
  3. Removing the lenticule changes the shape of the cornea, thereby achieving the desired refractive correction.

SMILE is a minimally invasive, flapless procedure that combines the advantages of the two previous generations. The overall treatment is gentle and visual recovery is fast.


To book a suitability appointment for one of the procedures mentioned, contact us on 028 9032 2020 or email

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Adventurous and sporty Optometrist Aaron had been wearing contacts since he was 13, until he had the groundbreaking VisuMax Smile Laser Eye procedure at Cathedral Eye Clinic. Read Aaron's comprehensive review of his experience.
Optometrist Can't Believe His Eyes!
Danielle Anne recently came to Cathedral Eye Clinic to have the groundbreaking VisuMax Smile Laser Eye procedure, and noticed a dramatic improvement in her vision just a few hours later. Danielle kindly wrote a few words to share her experience with Cathedral Eye Clinic and Medical Director Professor Moore.
Review: Danielle now "seeing the world in HD"