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LASIK vs SMILE: Which Laser Eye Surgery is Best?

Key Takeaways

BOTHBoth are effective, safe laser eye procedures when done well.
LASIKPatients treated with LASIK for one eye and SMILE the other, preferred the LASIK eye for better vision.
LASIKLASIK treats a wider range of prescriptions.
SMILESMILE eye surgery has a slower recovery but potentially less risk of dry eyes
SMILESMILE involves more corneal tissue removal.
BOTHConsult an ophthalmologist to pick the best option for your eyes.

Tired of vision problems? SMILE and LASIK both offer vision correction solutions. Both will get rid of your glasses or contact lenses.

But which eye surgery is right for you? This guide examines ALL the key differences to help you decide.


LASIK and SMILE offer excellent and proven laser vision correction options. However, some critical differences between these technologies are essential to understand. LASIK eye surgery is the most popular laser procedure in the world, but SMILE eye surgery is gaining popularity.

  • LASIK stands for laser in-situ keratomileusis.
  • SMILE stands for small incision lenticule extraction.

SMILE is, in fact, a brand name from Carl Zeiss. The correct name for these procedures is lenticule extraction. The various brand names from different laser manufacturers are:

  • SILK (Johnson & Johnson)
  • CLEAR (Ziemer)
  • SmartSight (Schwind)
  • SMILE (Carl Zeiss Meditec)

Both LASIK and SMILE are refractive surgery procedures, meaning they correct for the need for glasses and contact lenses. Both laser eye surgery techniques have proven effective in providing excellent visual acuity and safety.

  • LASIK has been performed since 1991 (Pallikaris, Greece)
  • SMILE has been performed since 2008 (Sekundo and Blum, Germany)

The original SMILE laser eye surgery procedure, Flex, involved creating a flap. This was updated to eliminate the need for a flap and remove any flap complications. The procedure was later termed Relex SMILE before settling on just SMILE.

Dave Allamby, MD

The most apparent difference between LASIK and SMILE is the surgical techniques.

LASIK laser eye surgery involves creating a thin protective flap on the corneal surface using a femtosecond laser (or the outdated microkeratome blade). This flap is lifted to expose the underlying stromal tissues, which are then precisely reshaped by laser energy. 

SMILE, on the other hand, is a flapless procedure. A femtosecond laser is the only one used to make all the incisions. A tiny side cut allows access to remove an interior disc (lenticule) of corneal stromal tissue using the laser. There is no flap created at all. 

This flapless approach makes SMILE a less invasive procedure with reduced disruption of corneal nerves. However, it removes more tissue, thus potentially weakening the cornea more.

Vision Results: LASIK vs SMILE

Overall vision results are similar between LASIK and SMILE (lenticule extraction), except for patients who want to achieve the very best vision. In the chart below, based on recent research on SMILE versus LASIK, the number of patients who achieved 20/20 and 20/16 (one line better than 20/20) were similar.

However, LASIK led to far more patients achieving “supervision” of 20/12 (almost double 20/20 vision)

  • 55% of LASIK eyes could see 20/12 supervision
  • 15% of SMILE eyes could see 20/12 supervision
LASIK vs SMILE Results

Does LASIK or SMILE Give Better Vision?

Regarding visual outcomes, both technologies deliver 20/20 vision or better for most patients in clinical trials when performed expertly.

However, SMILE cannot yet perform customised treatment. Topography-guided LASIK and PRK are examples of custom treatments. They are performed using data from a 3D shape map to modify the laser correction to improve vision beyond that just by correcting the glasses prescription.

This research paper from 2017 compared topography-guided LASIK with SMILE, with LASIK giving noticeably better vision for 20/20 and 20/16 (one line better than 20/20).

SMILE vs LASIK vision results 2017

A 2022 research paper examined vision results between LASIK and SMILE. One year after surgery, a significantly higher proportion of LASIK eyes had 20/20 vision or better than SMILE eyes.

One year after LASIK and SMILE:

  • LASIK: 94% of eyes could see 20/20 or better
  • SMILE: 83% of eyes could see 20/20 or better
LASIK vs SMILE After One Year

Patients with healthy eyes achieve excellent final acuity, but SMILE recovery takes longer to achieve because SMILE surgery has a longer healing process.

Currently, the SMILE procedure can only treat short-sightedness and astigmatism. If you have longsight, SMILE is currently not an option.

Speed of Recovery: LASIK vs SMILE

If the speed of recovery is vital to you, LASIK is the clear winner:

  • SMILE patients report slower visual recovery, taking 1-7 days to reach 20/20 vision.
  • LASIK patients typically see better than 20/20 in 4-24 hours.
LASIk vs SMILE Vision Recovery

SMILE has a lower risk of post-operative dry eyes in the first few months since the protective tear layer is better preserved. However, by six months, dryness levels are similar with both procedures.

Is the LASIK Flap Better?

The flap in the LASIK procedure provides some advantages, too. It allows the surgeon to lift and reposition the corneal tissue more easily during treatment. This simplifies enhancements if the initial correction leaves a small refractive error, i.e., a prescription remains. 

With SMILE, a revision procedure (enhancement) is more complex. The surgeon has to switch and usually redo the surgery using PRK – a more painful treatment with a more prolonged recovery.

The flap also enables LASIK to be performed successfully in a broader range of prescriptions. It can safely treat up to around -12 diopters of myopia versus SMILE’s -1 to -10 diopters range.

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Experience of Each Surgery: LASIK vs SMILE

A 2023 research paper described 40 patients with LASIK in one eye and SMILE in the other. They asked the patients which eye they preferred.

Twelve months after surgery, 46% of participants preferred the vision from the LASIK eye compared with 19% for the SMILE eye.

Patient preference LASIK vs SMILE

More patients preferred vision from the eye that underwent LASIK compared with SMILE.

John Kanellopoulos

Both procedures are highly advanced, delivering outstanding results. However, LASIK has over 20 years of safety and efficacy data accumulated in millions of patients worldwide.

As a newer technology, SMILE lacks the same depth of long-term clinical evidence. Early results are promising, with stability comparable to the more established flap procedure.

For mild to moderate nearsightedness of up to about -6D, LASIK may be preferable for many patients due to the quicker recovery. It allows the treatment of a much wider range of prescriptions with enhancements that are simpler if needed. 

For long-sightedness, LASIK (or PRK for mild prescriptions) is the only laser refractive surgery option. For higher myopia, the SMILE procedure or ICL implants are good options.

LASIK & SMILE Treatment Ranges

Short-sight-0.50 to -14.00 D-0.50 to -10.00 D
Astigmatism0 to 6.00 D0 to 5.00 D
Long-sight0.50 to +6.00 DNot approved

How much of your prescription can LASIK and SMILE treat? You can see in the table above that LASIK can treat a but more astigmatism and 4.00 dioptres more of short-sightedness.

Therefore, LASIK has a much wider treatment range. The numbers are based on clinical effectiveness and safety approval studies by various regulatory agencies. However, implantable contact lenses (ICLs) are usually used to treat such high prescriptions since around 2020.

Another option can be refractive lens exchange (RLE) surgery for patients aged 45-50 and older.

LASIK SMILE Approval Treatment Ranges

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How Does LASIK Correct Vision?

LASIK corrects your refractive error (vision problems needing glasses) by reshaping the cornea using an excimer laser after flap creation.

  • Numbing eye drops applied.

  • A suction ring is placed on the cornea to keep it steady.

  • A femtosecond laser creates a thin flap in your cornea.

  • The flap is lifted to access the inner corneal tissue.

  • An excimer laser ablation sculpts this tissue.

  • The flap is replaced.

  • Antibiotic drops are used for one week.

The laser surgery flattens the cornea, adjusting focus and reducing refractive errors like nearsightedness.

Benefits of LASIK Surgery

  • Wide prescription range treatable: nearsightedness, farsightedness, astigmatism.

  • High success rate: FDA trials showed almost 99% satisfaction rates.

  • Quick recovery: LASIK patients like that they can resume routine activities within 1-2 days.

  • Lasting results: Over 90% have stable vision ten years after LASIK.

  • Improved quality of life: Less need for glasses or contacts after.

Potential LASIK Drawbacks

  • Dry eyes: Temporarily common, sometimes chronic, requiring drops.

  • Flap complications: Rare risks like infection or abrasion.

  • LASIK involves creating a corneal flap, making it less suitable for contact sports.

  • Regression: More likely in very high prescriptions. Enhancements may be needed.

  • Unsuitable for some: thin cornea, severe dry eyes, autoimmune disease, etc.

  • LASIK requires more care in the first week after treatment.

How Does SMILE Correct Vision?

The SMILE procedure also uses a femtosecond laser but without creating a flap.

  • Numbing eye drops are applied.

  • A suction ring is placed on the cornea.

  • The laser forms tiny access cuts on the cornea.

  • Laser pulses dissect a lenticule (disc) of tissue inside the cornea.

  • The lenticule is extracted through the access cut.

  • The keyhole incision access cut seals itself. No stitches are needed.

  • Antibiotic eye drops are needed for one week.

This changes corneal curvature and shape, correcting nearsightedness and astigmatism like LASIK.

Benefits of SMILE Surgery

  • Less invasive procedure: No flap means less disruption of corneal nerves.

  • Less dry eye: SMILE has a lower dry eye risk than LASIK in the initial months (but not later).

  • Excellent results: Over 98% success in treating mild to moderate myopia.

  • Better for contact sports.

  • A smaller incision is made.

Potential SMILE Drawbacks

  • Limited prescription range: Typically only treats up to -10D of nearsightedness.

  • SMILE cannot yet treat long-sightedness.

  • More chance of blurry vision on the following day.

  • A longer recovery period (not shorter as often claimed).

  • Newer procedure: Less long-term data than established LASIK surgery.

  • It cannot treat higher-order aberrations through wavefront-guided LASIK.

  • Slower stabilization: Vision fluctuates more in the initial months post-surgery.

  • Less availability: Only done by SMILE-trained surgeons.

Key Similarities Between LASIK and SMILE

  • Both use advanced femtosecond lasers for precision and accuracy.

  • Both are laser-assisted procedures.

  • Neither can treat thin corneas; better to have PRK laser eye surgery.

  • Both must be performed on healthy eyes.

  • Both can treat short-sight and astigmatism.

  • Most patients can return to work after 1-2 days.

  • Both are convenient outpatient procedures taking 5-10 minutes per eye.

  • Both are tailored to the unique prescription needs of each eye.

  • Both offer a substantial reduction in the need for glasses or contacts after.

Key Differences Between LASIK and SMILE

  • LASIK creates a corneal flap, SMILE does not.

  • LASIK may achieve “supervision” for more patients than SMILE
  • There are many more LASIK eye surgeons than SMILE surgeons.

  • LASIK treats a wider range of prescriptions.

  • SMILE has a significantly slower visual recovery time.

  • LASIK has more long-term data available.

  • SMILE has a potentially lower risk of chronic dry eye side effects, but data suggest the results are similar at 6-12 months after treatment.

  • SMILE cannot yet treat long-sight.

Have a question about Laser Eye Surgery? Get in touch today

Choosing Between LASIK and SMILE

Each has its own benefits. The most suitable procedure depends on the following:

  • Your ophthalmologist’s recommendation is based on your eye health and prescription.

  • If you have thinner corneas – PRK is likely a better eye surgery option.

  • LASIK has a wider treatable range of refractive errors and works well for higher prescriptions.

  • SMILE treatment may be preferable due to less initial dryness.

  • Consider the experience and patient outcomes of your surgeon. LASIK patients are more likely to find a very experienced eye surgeon.

  • Both LASIK and SMILE treatments are not cheap. SMILE tends to be more expensive. Evaluate the costs and insurance coverage applicable to you.

  • The whole procedure in each case lasts 5-7 minutes per eye.

The optimal choice depends on the patient’s specific cornea health, lifestyle needs and vision goals. A detailed pre-operative examination and in-depth consultation will guide you on the best laser vision correction option for your eyes.

Frequently Asked Questions

How much do LASIK and SMILE cost?

The average price per eye is around £2,000-£2,500 for LASIK (per eye) and £2,300-£2,800 for SMILE (per eye). Many factors affect the final pricing.

Does insurance cover laser eye surgery?

Most insurance plans consider laser eye surgery elective, so they don’t offer coverage. Some may partially reimburse based on vision benefits.

What are the risks and side effects of SMILE vs LASIK?

Both procedures are very safe when performed by an expert refractive surgeon. Risks include dry eyes, infection, and flap complications (LASIK only).

How long does recovery take after LASIK and SMILE?

With LASIK, vision stabilizes within 1-2 days for most people. With SMILE, vision stabilizes within 1 week in many cases and improves over the next month or so.

What is the success rate of SMILE vs LASIK?

When done properly, both procedures have over 95% success rate in clinical trials for treating nearsightedness and astigmatism.

When can I return to work after LASIK or SMILE?

Most patients can return to their normal routine within 2 to 4 days. Strenuous activities may require two weeks’ rest.

How long do SMILE vs LASIK results last?

Studies show over 90% have stable vision correction beyond ten years after LASIK. SMILE is slightly less studied long term but shows excellent stability.

Am I too old for LASIK or SMILE?

There is no strict age limit. Those 40+ may eventually need reading glasses. Consult your ophthalmologist.

What about SMILE vs PRK?

PRK is an excellent option, especially if you have thin corneas. However, PRK will have a longer recovery process and more pain postop. SMILE small incision lenticule extraction is more often compared to LASIK.

Should I get LASIK or SMILE?

There is no definitive “superior” procedure. Follow your eye doctor’s recommendation on which is better suited for your eyes.

Next Steps

Want to learn more about laser eye surgery? Get in touch with Dave Allamby, MD.

Have a question about Laser Eye Surgery? Get in touch today

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