Difference Between LASIK and LASEK

Difference Between LASIK and LASEK

May 19, 2022

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If you’ve been researching refractive surgery, you’ve probably heard of them both: LASIK and LASEK. You may have also come across others, like SMILE and PRK. These are all different refractive surgery techniques designed to treat nearsightedness, farsightedness, and astigmatism.

But while LASIK and LASEK are similar, what’s the difference between them? First, let’s start with definitions. LASIK is an acronym for laser-assisted in situ keratomileusis, while the LASEK meaning is laser subepithelial keratomileuses. But what does that tell you? Don’t worry. This short guide will go over all the details about LASEK vs LASIK.

What Is Laser Eye Surgery?

There are various lasers used in eye surgery; the ones we most commonly think of when it comes to laser eye surgery are those used to reshape the cornea, which is the clear layer on the front of the eye. By reshaping this tissue, a refractive error can be reduced or eliminated. Refractive error refers to light not bending as it should when it hits the eye. This causes blurry vision. Myopia (nearsightedness), hyperopia (farsightedness), and astigmatism are all types of refractive error. So, while there is a difference between LASIK and LASEK, their similarity lies in that they are both laser eye surgeries.  


Some people are candidates for multiple types of refractive surgery, such as LASIK, LASEK, SMILE, or PRK; others may only qualify for one or some of them. If you’ve got the option to choose LASIK or LASEK, how will you know which is better for you? Here, we’ll go over the difference between LASIK and LASEK, highlighting the benefits and drawbacks of each one. 

What Is LASIK?

LASIK starts with the creation of a flap in the outer cornea, which is often done using a femtosecond (extremely fast-pulsed infrared) laser. The LASIK flap is made up of the outermost layer of the cornea, the epithelium, and a portion of the deeper layers, Bowman’s layer and the stroma. This flap is then lifted and an excimer laser is applied to the cornea to ablate or reshape it. The laser is instructed to deliver exactly the right amount of energy to correct a patient’s myopia, hyperopia, and/or astigmatism. The flap is then realigned over the treatment area to provide protection and facilitate healing, which is why recovery is so fast with LASIK.

What Is LASEK?

In LASEK, there is no flap created. Rather, the epithelium, meaning the outer layer of the cornea, is temporarily removed using alcohol and an ultra-thin sheet. The alcohol helps to dissolve the epithelial cells. The sheet is then applied and slid over the cornea to move the cells off to the side. This gives the surgeon access to the deeper corneal tissue for permanent corneal reshaping. The excimer laser is then applied to the cornea to ablate the tissue according to the exact calculations determined to be appropriate to correct a patient’s refractive error. The LASEK definition is laser subepithelial keratomileusis, which highlights where the treatment is delivered, directly underneath the corneal epithelium.

Unlike LASIK, where two lasers are often used, one to create the flap and one to reshape the cornea, LASEK only uses a single laser. 

After the laser treatment has been delivered in LASEK, the epithelium is slid back over the cornea to protect it during the healing process. Because this layer is only a single cell layer thick, a bandage contact lens is also applied to help with corneal protection and healing. 

Visal recovery can take a little longer with LASEK than with LASIK, but ultimately the visual outcome is similar. By avoiding the creation of a flap, however, flap complications are eliminated. This could be of benefit to those who engage in contact sports, for example, since they have a higher risk of flap dislodgement.

Since the development of PRK, many practices now use that method over LASEK.

What Is LASEK?

What to Choose: LASIK or LASEK 

LASEK and LASIK are similar procedures, with the main difference lying in whether or not a flap is created. After the cornea is prepared, both procedures involve the removal of corneal tissue. The higher the refractive error, the more tissue needs to be removed. In order for this to be safe, the corneal thickness must be measured preoperatively to ensure that there will be sufficient tissue remaining after surgery. 

In LASIK, the flap compromises extra tissue, as compared to LASEK. Therefore, some people with thin corneas and/or high refractive error may be candidates for LASEK but not LASIK. 

Benefits of LASIK

  • Fast healing time
  • Quick vision recovery
  • Minimally invasive
  • Minimal discomfort
  • Fewer complications

Benefits of LASEK

  • Useful in thinner corneas
  • Advantageous for high refractive error
  • Lower risk of dry eyes
  • No risk of flap complications
  • The visual outcome ultimately comparable to LASIK

So, What’s the Difference?

So, is LASEK better than LASIK? Neither, really. Both LASIK and LASEK are common refractive surgeries for the eye with great outcomes. The main difference between them lies in the corneal preparation before laser ablation is performed. Some people may be candidates for both procedures, while others may only qualify for one. As mentioned above, the development of PRK has caused many practices to phase out LASEK procedures. The preoperative examination is a detailed one that involves multiple measurements to determine which procedure is best for a particular individual.

Ultimately, your doctor can tell you which procedure is the best fit for you personally. Still, got questions about LASIK or LASEK? Call Kraff Eye Institute to schedule your consultation today.

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Dr. Colman R. Kraff

Committed to advancing new technologies in the field of ophthalmology, Dr. Colman Kraff helped to pioneer laser vision correction. In February of 1991, as part of a five-site, U.S., FDA clinical trial team, Dr. Kraff successfully performed the first excimer laser procedures in the Chicagoland area using the VISX Excimer Laser.

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