Can your prescription tell you whether SMILE is suitable?
SMILE may be an option for some people with high myopia, but your prescription alone cannot tell you whether it is suitable. The decision also depends on corneal measurements, prescription stability and the health of the rest of your eye.
Bring your current and previous prescriptions so the ophthalmologist can check for changes. Even if your prescription falls within a device's published range, your corneal shape, thickness and proposed treatment still need to be assessed.
Sources: SNU: SMILE pro, SMILE and LASIK
Why do corneal thickness and shape matter?
Corneal thickness helps the surgeon work out how much tissue can be removed. Topography or tomography maps the shape of the cornea. These results are reviewed together with your prescription and the amount of tissue that would remain after treatment.
An irregular shape or signs of keratoconus or ectasia may change the recommendation. A thickness measurement alone cannot confirm that surgery is suitable. Ask your ophthalmologist to explain your scan and how it affects the treatment plan.
Sources: SNU: SMILE pro, SMILE and LASIK · ZEISS: SMILE side effects and complications
Why does the retina need attention with high myopia?
High myopia is linked to a greater risk of retinal detachment, so the retina also needs attention when you are considering vision correction. Your assessment may include a dilated retinal examination. Surgery to correct your prescription does not treat a retinal tear.
Seek immediate eye care if you notice a sudden increase in floaters, flashes of light or a dark curtain or shadow across your vision. This applies whether or not you have had vision-correction surgery.
What are your options if SMILE is unsuitable?
If SMILE is unsuitable, glasses, contact lenses or another type of surgery may be options. ICL may be considered, but it has its own requirements for the space inside the eye, corneal endothelial cells and overall eye health.
A thin cornea or high prescription does not automatically make ICL suitable. Our ICL vs SMILE guide compares the examinations and risks, and the ICL examination guide explains how lenses are selected.
Sources: SNU: SMILE pro, SMILE and LASIK · SNU: ICL examinations and lens planning · FDA: assessing suitability for phakic lenses
Do published prescription limits apply to you?
A published prescription limit applies to a particular device, approved use and country at a particular time. Check whether the limit refers to spherical power, astigmatism or spherical equivalent. Also check whether the document is about SMILE, SMILE pro or an implanted lens.
For example, the FDA's 2022 EVO/EVO+ approval summary describes an approved use of those lenses in the US. It does not set the rules for every procedure in Korea. Your ophthalmologist can explain the approved use in Korea and how it applies to your full examination.
Sources: FDA: EVO/EVO+ approval summary (2022) · ZEISS: VISUMAX 800 and SMILE pro
Before you book
Planning a visit to SNU?
Let us know which treatment you are considering, your preferred language and when you will be in Seoul. Ask how to prepare for your eye examination, what your quote includes and which follow-up appointments you will need.
Contact SNU Eye Clinic →