LASIK is the most common surgery doctors use to correct specific vision problems. Traditional LASIK and its variations are generally safe, effective, and long lasting, but LASIK isn’t a fix for every eye problem.

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Laser in situ keratomileusis, more commonly known as “LASIK,” is a laser eye surgery that helps correct problems with how light passes through the front of your eye. LASIK can reduce the need for contacts or glasses.

LASIK gained popularity for treating eye problems in the 1990s. Researchers estimate that doctors have treated 20 to 25 million eyes with LASIK over the past 25 years.

Read on to learn about LASIK, including what conditions it can treat, what to expect during the procedure, and potential risks.

Light enters the front of your eye through a clear layer of tissue called your “cornea.” From there, light passes through your lens, a curved structure that focuses light onto your retina. Your retina is a layer of special cells in the back of your eye that converts light to electrical signals for your brain to interpret.

LASIK can treat refractive errors by changing the curvature of your cornea. Refractive errors occur when the front of your eye doesn’t properly focus light onto your retina.

LASIK can potentially treat:

An ophthalmologist will perform the LASIK procedure, which will likely occur like this:

  1. An ophthalmologist will insert eye drops into your eyes to numb them.
  2. They’ll use an eyelid holder to keep you from blinking and a suction ring to keep you from moving your eye. You’ll feel some pressure from the suction, and your vision will dim or go black.
  3. They’ll make a thin flap in your cornea, about the thickness of a sheet of paper, with either a laser or mechanical device.
  4. They’ll lift the flap and fold it back.
  5. They’ll ask you to stare at a light so that your eye doesn’t move and then reshape your cornea with the laser.
  6. They’ll fold your eye flap back down after reshaping your cornea and put it back into position. It will usually settle into place in about 2 to 3 minutes.

There are several variations to the LASIK procedure, including:


IntraLASIK stands for “IntraLase femtosecond laser-assisted LASIK.” IntraLASIK involves making the flap in your cornea with a femtosecond laser instead of a mechanical device.

A 2020 review reports that the two methods are equally effective, but IntraLASIK may have a higher risk of diffuse lamellar keratitis, a type of noninfectious inflammation.

Custom LASIK

Custom LASIK involves measuring your eye with a special laser to create a 3D image of your eye to guide the creation of the flap. The image enables doctors to treat more irregularities in the curvature of your cornea with greater precision.


Epipolis LASIK (Epi-LASIK) removes the outermost layers of the surface of your cornea (epithelium) to construct the flap. A laser then reshapes the cornea as it does in traditional LASIK. After reshaping, the ophthalmologist puts the delicate flap back into place.

Epi-LASIK is an alcohol-free variation of photorefractive keratectomy (PRK) surgery.

Before your procedure, an eye doctor will:

  • measure the size of your pupil and cornea
  • check for other problems with your eyes
  • test your vision
  • talk with you about your goals and expectations

The Food and Drug Administration (FDA) recommends switching to glasses full-time instead of contacts before your evaluation with a doctor.

Your eyes may burn or feel scratchy for several hours after your procedure. Many people can see clearly within a couple of days, but it can take up to 3 to 6 months for your vision to stabilize.

According to the American Academy of Ophthalmology, about 90% of people who undergo LASIK have vision between 20/20 and 20/40 without using glasses or contacts.

How long do the benefits of LASIK last?

The results of LASIK are permanent, but you may continue to have age-related changes to your vision. In a 2017 study, researchers found visual acuity (the ability to distinguish shapes) gradually decreased over a 12-year observation period after LASIK.

Learn more about how long LASIK lasts.

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Most of the side effects of LASIK are temporary, but they can be permanent in rare cases.

Almost everyone who undergoes LASIK will experience dry eyes and changing vision throughout the day for up to a month after the procedure. Other side effects may include:

Rare but serious risks of LASIK may include:

Flap displacement

The flap that rests over your reshaped cornea doesn’t go back to the way it was before. The flap only heals slightly around the edges but not in the center. This means that the flap can become dislodged.

About 1% to 2% of people who undergo LASIK displace their flap within 2 days of the procedure. Replacement is most often due to rubbing eyes or the movement of eyelids.

Although the risk is greatest in the days following the procedure, you can still displace the flap several years later.

To be a candidate for LASIK, you should:

  • be more than 18 years old and ideally more than 21 years old
  • have had little change in your vision prescription in the last year
  • have a condition that can be treated with LASIK
  • have a healthy cornea and good overall eye health
  • have realistic expectations

LASIK can’t correct presbyopia, an age-related loss of near vision.

Here’s a look at how LASIK compares with other types of laser eye surgery.

Type of surgeryDescription
LASIKA laser creates a flap in your cornea to reshape it.
photorefractive keratectomy (PRK)Doctors use alcohol to remove the outermost layer of cells of your cornea so that a laser can reshape the inner part of the cornea (stroma).
small-incision lenticule extraction (SMILE)A laser reshapes the stroma without making a flap. Instead, the surgeon will make a small incision to remove a thin layer of the stroma.
laser-assisted subepithelial keratectomy (LASEK)LASEK is similar to LASIK, but the flap only includes the outermost layers of your cornea.
laser-blended vision (LBV)This type of laser surgery treats presbyopia.
phototherapeutic keratectomy (PTK)Doctors use this procedure to treat disease or injury of the cornea.
advanced surface ablation (ASA)Doctors often use this progressive form of PRK to correct refractive errors for people who aren’t candidates for LASIK.

Here are some frequently asked questions people have about LASIK.

What is the age limit for LASIK procedures?

There’s no absolute cut-off age for LASIK, but older adults may have more health and eye issues that affect their candidacy. In a 2018 study, researchers found evidence that LASIK can be effective in select candidates more than 65 years of age.

Can you have multiple LASIK procedures?

It’s possible to receive LASIK more than once. Whether you can receive another surgery depends on factors such as your overall eye health and your corneal thickness.

How much do LASIK procedures cost?

The cost of LASIK may vary widely based on factors such as your geographic location, the clinic you visit, and the type of LASIK you receive. Prices tend to range from $1,000 to $4,000 per eye.

Learn more about the cost of LASIK.

Does insurance cover LASIK?

Insurance rarely covers LASIK surgery because most plans consider it an elective surgery. Your plan is more likely to offer coverage if you have a qualifying condition such as:

  • corneal ectasia
  • extreme irregular astigmatism
  • abnormal corneal surface issues
  • traumatic injury to your cornea

LASIK is a type of laser eye surgery that reshapes your cornea. Doctors use LASIK to treat conditions such as farsightedness, nearsightedness, and astigmatism.

LASIK is very common and has a low likelihood of risks. It’s important to discuss your surgery goals and expectations with a doctor before your procedure. Although rare, serious risks such as vision loss can occur.