What is SMILE Eye Surgery?

As vision correction technology improves, people struggling with vision issues have more options to consider. 

Of course there are glasses as a standard option, which can be used to correct a wide variety of vision issues, as well as contact lenses that are advancing at a rapid pace in terms of their comfortability, technology, and effectiveness.

In addition to these tried and true vision correction methods, there are also various types of laser refractive surgeries that can be considered as options as well. One of the newer refractive surgery options is called SMILE.

However, refractive surgery is not for everyone. It’s important to remember that surgery can have disadvantages compared to contact lenses depending on your type of vision issue and its severity, as well as cost and comfort considerations.

What is SMILE Eye Surgery?

A much newer option is known as the SMILE procedure, which stands for small incision lenticule extraction.

SMILE was FDA approved in the U.S. in 2016 (comparatively, LASIK has been around for over 30 years). SMILE is gaining ground on LASIK in terms of popularity due to its comparable outcomes while avoiding the negatives of LASIK (flap) and PRK (slow visual recovery and discomfort), and may someday be the standard procedure that is performed. However, SMILE is not without its own risks.

How SMILE Works

The process of SMILE eye surgery is a bit different from other laser refractive surgery methods. Think of the cornea as a round cake with frosting on it, viewed from above. 

While PRK in this analogy is like scraping the frosting off and lasering the top portion of the cake, and LASIK is like making a thin slice below the layer of frosting and into the cake to lift it up and out of the way before lasering, SMILE instead bypasses the frosting and top layer of cake to focus it’s beam deeper down into the cake. 

In doing so, it’s able to create a small cutout layer of cake (tissue) that is then removed through a small incision closer to the edge of the cake. As it is removed, the top layers collapse down slightly, which is what changes the shape of the surface.

Pros of SMILE

Being developed more recently with more recent technology, there are many advantages to SMILE eye surgery in comparison to other methods.

There are no complications from cutting a flap and more structural integrity to the cornea afterward compared to LASIK. 

A much smaller incision than what is used in creating the LASIK flap also means less incidence of dry eyes, since not nearly as many corneal nerve endings are cut with the small incision of SMILE.

Cons of SMILE

Though SMILE is newer, there are drawbacks to this method.

It is more limited in the treatment amounts that can be done for nearsightedness and astigmatism, and currently cannot be used for farsighted patients. 

There is also slower healing and vision recovery compared to LASIK, but still faster than PRK. 

Visual outcomes are comparable to LASIK, but LASIK still has a slight statistical edge in long-term studies so far.

One other factor is that if retreatment is ever needed for an under or over-correction, SMILE cannot be repeated. PRK and LASIK in most cases can be retreated if needed. It would be possible, however, to do a PRK retreatment over an existing SMILE treatment if it was necessary.

Comparing SMILE to Other Laser Refractive Eye Surgeries

The types of laser refractive eye surgeries all work a little differently. Here is a diagram to help visually show the difference between these procedures and how they work.

Unlike PRK or LASIK, SMILE penetrates beneath the epithelium without removing it or creating a flap, which allows access to the cornea to reshape it with the laser.