What Is ReLEx SMILE Surgery?

ReLEx SMILE (Refractive Lenticule Extraction, Small Incision Lenticule Extraction) is a minimally invasive laser vision correction procedure used to correct myopia and astigmatism.

It uses a femtosecond laser to create a thin disc of tissue (a lenticule) inside the cornea, which the surgeon then removes to change its shape. By changing the shape of your cornea, ReLEx SMILE can correct the aforementioned refractive errors.

In this article, you’ll learn exactly how SMILE works, who makes a good candidate, the procedure's risks and benefits, and what you can realistically expect.

What to Expect from the Procedure

Before undergoing laser eye surgery, your ophthalmologist will talk through your expectations to ensure you know exactly what you’re getting. Some people might still have to wear glasses or contact lenses for certain activities after laser eye surgery. 

But most people can carry out most of their day-to-day tasks without them. After discussing and managing expectations, your ophthalmologist will conduct an eye exam to ensure you are suitable for the procedure. 

This will include:

• An eye test to determine if you’ll benefit from SMILE
• Digital corneal mapping to take several measurements of your cornea’s surface and thickness
• Measuring your pupil size

What Happens During the Procedure?

Before this refractive surgery, your doctor will administer numbing eye drops. They will use a speculum to prevent you from blinking.

The procedure consists of three main steps:

• A femtosecond laser will create a thin lenticule of stromal tissue, roughly the shape of a contact lens, inside the intact cornea. This is called a lenticule.
• It will also make a small incision (approximately 2 to 4 mm long) in the cornea.
• The ophthalmologist will remove the lenticule through the incision.

The laser portion takes about 30–60 seconds per eye, and the overall procedure typically runs ~10 to 20 minutes per eye, depending on the system and workflow.

During treatment, you might feel slight pressure but no significant discomfort. Patients often describe seeing flashing lights but report minimal pain.

What to Do After the Procedure

Most people will have hazy vision right after the procedure. Don’t drive until your surgeon confirms at a post-op exam that your vision meets legal standards.

While you’re recovering, rest your eyes and keep them closed, especially within the first few hours. Avoid certain things that can irritate your eyes, such as:

• Prolonged screen use and television.
• Dusty environments.
• Strenuous activities like heavy lifting or exercise.
• Touching or rubbing your eyes without washing your hands.
• Getting water directly into your eyes.
• Wearing makeup.

Be sure to follow your doctor’s prescription for antibiotic and steroid eye drops to prevent infection and reduce inflammation. You can also use artificial tears to relieve dryness as needed.

Be sure to contact your surgeon if you experience severe pain, infection, or sudden vision changes.

How Much Does SMILE Cost?

In the U.S., the cost of SMILE generally ranges from about $2,000 to $4,000 per eye. The overall price is influenced by factors like the surgeon’s expertise, the technology used (such as the ZEISS VisuMax laser), and the clinic’s location.

ReLEx SMILE surgery is considered elective, meaning insurance typically does not cover the cost. However, you can often use funds from Flexible Spending Accounts (FSA) or Health Savings Accounts (HSA) to offset expenses.

You can also ask your insurance provider or surgeon whether they’ll cover the costs of SMILE surgery. 

Who is a Good Candidate for the Procedure?

Not everyone qualifies for SMILE. Your eye health, prescription stability, and overall medical history are crucial in determining your eligibility for SMILE.

Here’s a quick candidacy checklist:

• You must be at least 22, with a stable prescription for 12 months or more.
• Myopia −1.00 to −10.00 D with up to −3.00 D of astigmatism.
• You need an adequate residual stromal bed (typically ≥250 to 300 µm) and sufficient corneal thickness.

You won’t be considered for SMILE if you’re suffering from an eye disorder or infection, autoimmune diseases that affect healing, or if you are pregnant or nursing.

What are the Pros and Cons of ReLEx SMILE?

SMILE offers several clear advantages compared to other procedures like LASIK or PRK, though it also has limitations you should consider carefully.

What are the Side Effects of SMILE?

As with any surgical procedure, SMILE does come with its own side effects and potential risks. Some of the most common side effects include dryness, inflammation, glare, and halos.

Rare complications can include:

• Over and under-correction
• Cap tears or epithelial ingrowth
• Infection
• Ectasia (a rare but serious weakening of the cornea)

Your surgeon will use precise corneal topography and screening to lower these risks significantly. If complications arise, prompt treatment can usually resolve them effectively.

Is the Procedure Effective?

The U.S. Food and Drug Administration (FDA) approved the VisuMax Femtosecond Laser for the SMILE procedure in September 2016. Studies have shown that SMILE resulted in vision equal to or better than 20/20 in 84% of participants at 6 months.

Other studies report 84% to 88% at similar follow-ups. SMILE is effective, stable, and safe, but ongoing research on the procedure continues.