ReLEx SMILE

1. What is SMILE

SMILE (Small Incision Lenticule Extraction) procedure re-shapes cornea and corrects vision without cutting corneal flap. The principle is to use advanced Zeiss laser (Visumax) to create a thin Lenticule (precise lens-shaped disc within the cornea), which is then removed through a tiny small corneal incision. This procedure changes the corneal curvature and thus correct vision. SMILE can correct myopia and astigmatism at the same time.

  • Correct Up to -10.00D of Myopia and up to -5.00D of Astigmatism 
  • Corneal wound is greatly reduced by nearly 80%, that’s why infection is even less likely, and the eye feels less dry: Less nerves are cut
  • No corneal flaps mean there is no flap related complications. Corneal biomechanical integrity is better-preserved which lead to improved dry eye problem


2. Am I a Suitable Candidate for SMILE

In general, if you fulfill the requirements below, you are a suitable candidate:
  • At least 18 years old
  • No health issues which affect your eyes
  • No special issues which influence the healing of wound
  • Having a stable contact lens or glasses prescription 

3. How to Schedule an Appointment

To make sure if SMILE is suitable for you, you should have a comprehensive eye examination at our centre. Please attend one of the seminars to obtain more information about refractive surgeries. The seminar is totally free. Please make your reservation by contacting 2628 1111 or online at https://www.hklasereye.com/en/booking.

Then you can make a complete eye examination and evaluation. Book the date of surgery if you are suitable for SMILE. Before the eye examination and surgery, you must stop wearing:

  • Soft contact lens: 7 days
  • Hard or gas permeable lenses: 3 weeks
  • Ortho-K lens: 3 months

4. Pre-Operative Preparation

The full eye examination takes around 1.5 hours to 2 hours. The examination includes:

  1. Auto-refraction, trial lens to find out the accurate refraction and eyesight.
  2. Use computerised machine to scan and measure the corneal shape, thickness and curvature of your eyes.
  3. Check the back of your eye
  4. Dilation of pupils to check the retina

After pupil dilatation:
  • Your vision will be blurry with near reading
  • Light halo
  • No same-day SMILE procedure
  • Bring a pair of sunglasses(your eyes will be sensitive to the sun)
  • Do not drive on the day of the eye examination
  • The impact of pupil dilation will disappear in 4 to 6 hours 

5. SMILE Procedure

  • The laser places a series of pulses in the centre of the cornea. These pulses outline the tissue that needs to be removed to effectively change the shape of the cornea
  • Removing the lenticule through a small incision of 2mm-4mm
  • The shape of the corner is changed

During the procedure, topical anesthetic eye drops are used to completely numb the eye. There is an eyelid speculum putting on the eye to prevent blinking. All you need to do is to look at a target light during the procedure.


Step 1: Lenticule Creation
A thin lenticule is created inside the intact cornea.


Step 2: Incision Creation
an access incision is created on the corneal surface that is less than 4mm wide.


Step 3: Lenticule Removal
The lenticule is removed through the laser-generated small incision with minimal disruption to the corneal biomechanics.


Step 4: Refractive Error is Corrected
Removing the lenticule changes the shape of the cornea, correcting the refractive error. The incision is so small that it will seal itself after some time.

6. Post-Operative Care

  1. It is normal that you may experience some discomfort after the procedure. Please take the pain-killers as prescribed by your doctor.
  2. You can resume your normal routine in 2-3 days.
  3. If the pain and discomfort is unbearable, or suffer from a vague vision in a short period of time, please consult the doctor immediately.
  4. Do not rub or scratch your eyes at any time.
  5. Please use the eye drops (antibiotics or steroid drops) as directed by doctor.
  6. You must return to the clinic for post-operative check up on the first day after the procedure.
  7. Avoid soap, tap water or contaminated water getting into your eyes for 1 week after the procedure.
  8. Avoid eye make-up until 2 weeks after the procedure.
  9. Use sunglasses to prevent UV light irritating your eyes.
  10. Avoid watersports until 15 days after the procedure.
  11. There may be some changes on your myopia, hyperopia or astigmatism for 3 months after the surgery.

7. Goals of SMILE

Convenience of Getting LASIK:

  • Clear vision without the inconvenience and limitations of corrective lenses
  • In case of danger, if you do not have glasses or contacts lenses on, you will not be able to help yourself or others
  • Able to see while putting on make-up or shaving
  • Glasses, especially with very strong prescriptions, can be quite thick and heavy and thus uncomfortable
  • More natural appearance without glasses
  • Chance of infection with contact lenses, so SMILE can eliminate risks associated with long term contact lens usage
  • No longer to spend time/money on buying/finding contacts, cleaning solutions or replacing lenses or glasses
  • Expanded career opportunities
  • Greatly increased recreational possibilities, may even improve performance in sports

8. Risks of SMILE

  • Under- or Over-correction
  • Corneal infection or inflammation
  • Increase light sensitivity, halo or glare around light source (many people experience poor night vision or night glare before SMILE)
  • Glare, haze and irregular astigmatism
  • A feeling of dry eyes and photophobia
  • Corneal epithelial Growth
  • Regression
  • Damage of vision
  • Keratoconus