Is ReLEx SMILE Surgery Better Than LASIK?

Written by Joshua Paul Harvey

MA(Oxon) BM BCh Pg Cert FRCOphth

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What is ReLEx SMILE?

ReLex SMILE or simply SMILE (small incision lenticule extraction) is a new and minimally invasive form of laser eye surgery which can reshape the front surface of the eye (cornea) and give you good vision without the need for glasses or contact lenses. The biggest advantage of SMILE over traditional laser techniques such as LASIK or LASEK is that it works beneath the surface of the cornea which reduces post-operative pain, speeds recovery and avoids damage to the ocular surface.1

Who is it suitable for?

SMILE surgery can treat a wide range of myopia (short-sightedness) from -0.50D to -12.50D. SMILE surgery can also be used to treat astigmatism (+/- 0.50D to +/- 5.00D).2 SMILE is also suitable for some patients who cannot have LASIK/LASEK such as those with thin or dry corneas.


Unlike LASIK/LASEK, SMILE surgery does not require the removal of the front of the cornea or the creation of a flap. This has several important advantages:

  • Post-operative pain is minimized and recovery is quicker.3
  • There is less chance of developing dry eyes after the procedure.4,5
  • There is no chance of “flap-related” problems after the procedure which is particularly important in people who engage in contact sport or are prone to rubbing their eyes.6
  • Patients who have thin corneas may be ineligible for LASIK/LASEK but can often still have SMILE surgery.7

However, SMILE laser eye surgery does have some potential disadvantages:

  • During the procedure the laser can lose suction onto the front of the eye which occurs around 1 in 200 cases (0.5%). Sometimes this means that the surgeon must stop the procedure and complete it 2-4 weeks later.8
  • Repeat treatments after SMILE laser can be more challenging and often require a different type of laser surgery.9
  • SMILE surgery is most effective for myopic (short-sighted) people. Whilst it is technically possible in hyperopic (far-sighted) people it is likely that an alternative laser method like LASIK/LASEK is more suitable.10

What happens during the SMILE procedure?

The procedure begins with the patient’s eye being numbed with local anaesthetic eye drops. Then the patient lies on a bed which slides under the laser and aligns the eye to the laser machine. The laser provides a gentle suction to keep the eye in a fixed position. The laser takes around 30 seconds to perform the procedure and then releases the suction. The surgeon will then complete the procedure by removing the lenticule made by the laser. The whole procedure takes around 5-10 minutes per eye.

How much does SMILE surgery cost?

SMILE laser surgery typically costs slightly more than traditional laser techniques. The exact cost often varies slightly depending on several things such as whether one or two eyes are to be treated and how large and what type of glasses prescription you have before the surgery. Below is a guide to how much you can expect to pay for SMILE surgery.

Company Price per eye
London Vision Clinic £2,600
My iClinic £1,900
Optegra £2,495
Laser Vision Eye Centre £2,200
Prices were obtained from company websites and were accurate as of Nov 2021.

Does SMILE cost more than LASIK/LASEK?

SMILE laser surgery typically costs £500-£1000 more per eye compared with LASIK/LASEK. This is predominantly because the equipment which performs the surgery is more advanced and expensive. For instance, the laser used in SMILE (femtosecond) costs around £1 – 2 million and must be regularly maintained. This is around 10 times the cost of the laser machine used in LASIK/LASEK (excimer). Additionally, only a few surgeons in the country are qualified to perform SMILE surgery.

What is the recovery period after SMILE surgery?

Local anaesthetic drops mean you will not feel any pain immediately after SMILE surgery. You may develop a dull ache in the eye which is normal and may last several days. Initially you will not be able to see well out of the treated eye. However, the vision will soon return to normal. You will be given eye drops to use after the surgery which are important to treat any post-operative pain and to aid visual recovery.

It is recommended to avoid heavy lifting and exercise up to 4 weeks after the laser surgery. It is important to not swim until you are told it is safe to do so. It often takes around 1 month before people are completely symptom free.


What is the difference between SMILE surgery and LASEK/LASIK?

SMILE surgery is a newer type of laser eye surgery. It has a faster recovery time and no flap related problems. See how SMILE compares to LASIK, LASEK and PRK treatments here.

What are the advantages of SMILE surgery?

There is less risk of dry eye, post-operative pain and flap related problems.

What are the disadvantages of SMILE surgery?

SMILE surgery is not suitable for everyone, particularly hypermetropic (far-sighted patients). Retreatment after SMILE surgery is also more challenging than after other types of laser surgery.

Can I see during the procedure?

Yes, you maintain vision throughout the procedure. However, the laser can cause some visual effects which do not last long.

Do I need stitches required/removed?

There are no stitches used in SMILE surgery. The incisions are small enough that they are self-sealing.

Can all types of refractive error be corrected by SMILE surgery?

SMILE surgery is best suited for myopia (short-sighted) and astigmatism. It is not typically used for hypermetropia (far-sighted).

How long does SMILE surgery take?

Around 10 minutes per eye.

Will I be awake during the procedure?

Yes. Patients have local anaesthetic eye drops to stop any pain during the procedure.

Is SMILE surgery painful?

No. You will be given eye drops to stop any intraoperative pain. You may feel a pressure on your eye which is normal.

Can I be treated more than once?

If a patient requires retreatment, they can be treated again but it is often by a different laser technique such as PRK or LASIK/LASEK.

Can both eyes be treated at the same sitting?

Yes, both eyes can be treated on the same day and are treated one after another.

When can I return to work?

Normally patients require 1-2 days off office-based work and 2-4 weeks off work if their job requires heavy lifting.