Doctor assists patient before LASIK


The widely-practiced laser eye surgery

LASIK treats refractive errors by folding away the top layer of the eye and re-shaping tissue underneath. If a femtosecond laser is used, this type of procedure is called Femto-LASIK.

  • What is LASIK?


    Folding back the top layer and reshaping tissue underneath

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    See how LASIK treats refractive errors

    LASIK, Laser-Assisted In Situ Keratomileusis, is a refractive laser procedure used to treat nearsightedness, farsightedness, and astigmatism. Since its invention in the early 90s, LASIK has been the most popular surgical treatment method to correct refractive errors. Like other laser eye surgeries, LASIK treats vision defects by reshaping the cornea to correct the way light is focused on the back of the eye.

    With LASIK, a surgeon creates a sliver of tissue, essentially making a flap, at the front of the eye to expose the inner layers of corneal tissue to the laser. Surgeons will either use a mechanical instrument, called a microkeratome, or a femtosecond laser, for this step. When a femtosecond laser is used, the procedure is called Femto-LASIK. Once the flap is folded away, an excimer laser shapes the cornea by removing the exposed tissue. The Femto-LASIK/LASIK procedure is completed when the surgeon closes the flap, returning it to its original position.


    Flap surgery: The surgeon creates a flap manually or with a laser. The top eye layer is opened to expose the inner layer of the cornea.

    Laser precision: After the flap is folded away, an excimer laser treats the eye for the individual refractive error. The laser only ablates the necessary tissue, leaving the surrounding tissue unaffected.


    Experience: LASIK has been the standard treatment for over 20 years. Many surgeons are very experienced with this procedure.

    Quick recovery: Typically, vision becomes clearer within a couple hours after surgery and gradually stabilizes over the following weeks.

    Availability: LASIK is currently the most popular and prevalent form of laser eye surgery. Nearly every clinic offering Laser Vision Correction has the technology available for this procedure.

    Potential Side Effects

    Like all surgical procedures, no intervention is completely free of risks and side effects. Your ophthalmologist can explain all potential risks to you and will decide whether you are eligible for surgery.

    However, these are some side effects that can occur after surgery.

    Flap-related complications: Complications with the flap after surgery may include infection, inflammation, and dislocation of the flap. While the flap usually adheres back onto the eye after surgery, it does not completely seal itself back together with the corneal tissue. Since the flap sits on the eye, there is a remote chance for it to be dislodged, especially during contact sports or other activities.

    Dry eye syndrome: This symptom can occur after LASIK vision correction surgery. Nerves cut during laser eye surgery may reduce the patient’s blinking frequency and/or give insufficient signals to the tear ducts. Blinking less frequently leads to the eye’s tear fluid evaporating faster than normal, which can result in the eye being less lubricated and drier. Dry eyes after LASIK can cause both discomfort and less optimal visual outcomes, but it typically improves or resolves with time.

    Further common complications and side effects of LASIK and alternative types of Laser Eye Vision Correction procedures are explained on the page that lists potential risks.

  • Treatment Steps


    Determining if LASIK is right for you

    Talk to your eye doctor about laser eye surgery as well as other solutions for your vision problem. Your doctor will decide if you are a suitable candidate for LASIK after completing several diagnostic tests. Together, you and your doctor can determine the best treatment option to suit your needs.

    Preparing for Surgery

    Before and on the day of surgery

    Patients are usually directed by their doctor to:

    • Stop wearing hard contact lenses for at least four weeks and soft lenses for two weeks before surgery, because they may interfere with preoperative diagnostic tests. 
    • Wear no make-up, perfume or lotion the day before the procedure. These products may leave debris around the eye and eyelashes, which increases your chance of infection. 
    • Arrange for alternative transportation after surgery, if you usually drive yourself, and possibly also for the next few days.


    What are the treatment steps of LASIK?

    Woman on surgical bed for LASIK

    Numbing the Eye

    To reduce pain during the surgery, anaesthesia drops are given to numb the eye. An eyelid holder is used to prevent the eye from blinking during surgery.

    A femtosecond laser creates a thin flap

    Immobilizing the Eye and Creating the Flap

    After the eye is numb, it needs to be immobilized for the surgery. This is done with a contact glass or suction ring which is gently placed on the eye. A slight pressure may be felt when this occurs. Once the eye is held stationary, the doctor will slice a thin layer of tissue from the top of the eye with either a mechanical device (microkeratome) or a femtosecond laser.

    Patient moving between lasers

    Changing to the Excimer Laser

    After the flap creation, the patient will be moved to the excimer laser for the next step of the procedure. Then the doctor will open the top layer of the eye – it is hinged back like an open book cover to expose the cornea.

    Excimer laser sculpts corneal tissue

    Sculpting the Cornea

    The laser will sculpt the tissue in the cornea to correct the refractive error. Sounds and a smell may be perceived, depending on the laser. Excimer lasers are equipped with an eye tracking system to follow and to compensate for eye movement during surgery.

    The flap in its original position

    Adhering the Flap

    The surgeon will return the flap to its original position. Within hours, the flap sticks to the underlying tissue without stiches.

    After Surgery

    Rest for a quick and easy recovery

    After surgery, it is recommended to:

    • Not rub the operated eye, rest and not overexert yourself
    • Wear protective glasses the day after surgery to prevent accidentally moving the flap by rubbing the eye
    • Wear a patch while sleeping for a week to avoid moving the flap
    • Use eye drops for some days following the surgery to prevent infection and alleviate dryness
    • Avoid strenuous contact sports for at least two weeks

    The flap should be stable within a matter of days but vision may fluctuate for several more months after the surgery. Doctors typically require a follow-up exam the day after and one a month after surgery.

  • Questions & Answers

    Frequently Asked Questions about LASIK

    • What advantages does Femto-LASIK offer over the classic LASIK method?

      The difference between the Femto-LASIK and the classic LASIK method is the way the flap in the cornea is created. A laser is used to cut the flap in Femto-LASIK. In the classic method, the surgeon opens the cornea manually with a microkeratome. The laser can be more precise and predictable in cutting the flap than manually with a mechanical device. However, eye surgeons do not have a uniform opinion that one method is more clinically superior than the other. The decision between the two is based on a patient’s existing conditions and the doctor’s preferences.