What is ReLEx ® SMILE?

ReLEx Smile ReLEx® SMILE (Refractive Lenticule Extraction, Small Incision Lenticule Extraction) is a minimally invasive, bladeless form of laser eye surgery which does not require the cornea to be ‘flapped.’ It corrects visual problems including shortsightedness and astigmatism (“san guang”) and is often suitable for patients with very high prescriptions, drier eyes, contact lens intolerance, and / or thinner corneas. Because no flap is created, the healing time is much faster than traditional LASIK. The procedure takes just a few minutes, with vision improving 80% immediately and reaching 100% in just a few days.

It is the next generation of laser vision correction surgery that uses only one femtosecond laser for the entire procedure. Unlike LASIK, it does not require the patient to change positions in order to pass from one instrument to the other, thus providing greater comfort and less time to complete the procedure.

Like most refractive eye surgery procedures, ReLEx® SMILE aims to reduce your dependency on spectacles and contact lenses in order to improve your quality of life , as shown by this  US National Insititute of Health study on ReLEX® SMILE.

ReLEx SMILE Treatment ReLEx® SMILE is an all-in-one laser procedure that takes about 10 minutes to perform on one eye. The actual laser process takes only about 30 seconds to complete. The entire ReLEx® SMILE is performed with gentle, low suction such that vision is preserved with no “black out” phenomenon, unlike other laser refractive procedures.



Step 1:In a single step, the VisuMax takes about 30 seconds to precisely create a refractive lenticule (a thin lens shaped cornea tissue) within the cornea inner layers & a small 4mm incision on the intact cornea surface.



Step 2:The refractive lenticule is then removed through the small incision. Cornea structure remains undisrupted & stable.



Step 3:The removal of the refractive lenticule changes the way light bends into the eye, allowing you to see clearly once again. The micro incision self heals.


ReLEx® SMILE is beneficial for those with higher degrees of myopia between 500 to 1000 degrees and astigmatism of up to 500 degrees.


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Minimally invasive 
Compared to LASIK, the incision is up to 80% smaller. Previously an incision of roughly 20 mm had to be created, whereas a small incision of less than 4 mm is now sufficient.

No LASIK-like flap 
No flap complications such as displacement and dislodgement.

Preserving upper corneal structure
As no corneal flap is created, the upper corneal structure remains practically untouched. Therefore the structural stability of the cornea will be largely unaffected.

Less post surgery dry-eye discomfort
Reduced post-operative discomfort from dry eyes, as the majority of the upper corneal structure remains untouched during treatment.
Night vision
Less induction of optical aberrations as no corneal flap is created.



ReLEx eye surgery aims to reduce the dependency on spectacles and contact lenses in order to improve the quality of life. Studies have shown that quality of life is reduced in spectacle wearers, particularly those with higher corrections. Read more about this topic at the US National Library of Medicine. Quality of Life Study:  ReLEx eye surgery vs. corrective lenses.


Laser vision correction surgery, also known as ReLEx eye surgery (or refractive eye surgery) refers to any surgical treatment using lasers to correct problems such as myopia, hyperopia and astigmatism. The treatment works by reshaping or polishing the cornea (the clear front portion of the eye), so that light traveling through it is properly focused onto the retina for a sharp and clear image. There are many types of vision correction surgeries and these include ReLEx® SMILE (Refractive Lenticule Extraction, Small Incision Lenticule Extraction), LASIK (Laser-Assisted in Situ Keratomileusis) and Surface ablation procedures such as Photorefractive Keratectomy (PRK), Laser Epithelial Keratomileusis (LASEK) or Epithelial Laser in Situ Keratomileusis).


Surface ablation is a laser refractive procedure where the corneal epithelium is removed before laser ablation is applied to the underlying stroma in order to reshape the corneal surface. In myopia, the central corneal surface is flattened allowing the accurate re-focusing of light entering the eye. In hyperopia, the peripheral corneal surface is flattened instead. A period of 3 to 5 days after surface ablation surgery is needed for healing during which time pain or discomfort is usually experienced. A bandage contact lens is used to aid healing. Visual recovery takes weeks to months before refractive stability is achieved at about 3 to 6 months. In general, surface ablation is performed on patients with either too thin or too steep corneas in order to preserve corneal strength. Occasionally, it is also performed on patients who participate in contact sports or on those who desire a flapless procedure. The advantages of surface ablation include:

  • No flap related complications
  • Tissue saving
  • Good outcome for lower degrees of myopia and astigmatism

The disadvantages of surface ablation include:

  • Post surgical pain of 3 to 5 days
  • Longer visual recovery
  • Longer use of eye medications
  • Increased risk of corneal haze (i.e. cornea scarring)
  • Slightly increased risk of corneal infections during the healing phase
  • Less predictable outcome for patients with higher corrections

Photorefractive keratectomy, Laser assisted subepithelial keratectomy (LASEK) and Epithelial Laser in Situ Keratomileusis (Epi-LASIK) are all surface ablation procedures and only differ in the method of epithelium removal. They all achieve equivalent visual acuity results.


Photorefractive keratectomy is a surface ablation method where the corneal epithelium is removed manually with a blunt instrument.


LASEK (Laser assisted subepithelial keratectomy) is a method of surface ablation where the corneal epithelium is removed with dilute alcohol solution.


Epi-LASIK (Epithelial Laser in Situ Keratomileusis) is a surface ablation technique where the surface epithelium is cleaved off using a blunt automated blade called an epitome.


LASIK (Laser assisted in-situ keratomileusis) is one of the most popular laser vision correction procedures. A corneal flap is created using a femtosecond laser or mechanical microkeratome. If the femtosecond laser is used to create the flap, then the procedure is considered ‘Bladeless’. The corneal flap is folded back to expose the underlying corneal bed and to allow excimer laser ablation to occur. Laser excimer ablation is necessary to reshape the corneal surface so that refractive errors can be treated. The flap is then replaced back into its natural position and smoothened. LASIK is performed with numbing eye drops only and both eyes are usually treated at the same time. The entire process may take around 15-30 minutes. Typically, visual recovery occurs in the first week following surgery and the eye may feel irritated for a day or so only. Medicated eye drops are prescribed for 1 week afterwards. There is usually little down time after LASIK and patients are able to participate in most activities with the exception of water sports for the first month. The key advantages of LASIK include:

  • Fast visual recovery
  • Little postoperative discomfort

The disadvantages of LASIK include:

  • Flap related complications. E.g. striae or folds, inflammation, epithelial ingrowth, retained debris and traumatic dislodgement