LASIK or SMILE — which should I choose? An honest comparison

Patients often arrive having already researched this question for weeks. They have watched videos, read forums, and sometimes they walk in saying “Doctor, I’ve decided I want SMILE” or “My friend had LASIK, I want the same.” I appreciate the homework. But I always give the same honest answer: your cornea decides, not your preference. Let me explain why.

How LASIK works

In LASIK, we first create a thin, hinged flap on the surface of the cornea. The flap is lifted, an excimer laser reshapes the corneal tissue underneath to correct your power, and the flap is laid back in place, where it settles naturally without stitches. The whole procedure takes minutes per eye, done under anaesthetic drops.

LASIK has decades of results behind it, it corrects a very wide range of powers including cylinder (astigmatism), and visual recovery is famously quick — most patients see well by the very next morning.

How SMILE works

SMILE takes a different route. Instead of a flap, a femtosecond laser — in our hands, the ZEISS VISUMAX 800 — creates a thin, precisely shaped disc of tissue called a lenticule inside the intact cornea. I then remove that lenticule through a small keyhole incision of a few millimetres at the edge. Removing the lenticule reshapes the cornea and corrects your power.

The key difference is what is not done: there is no flap. The outer layers of the cornea stay almost entirely intact, disturbed only at that small keyhole.

Recovery and dry eye — the real differences

Both procedures are quick and essentially painless, and both give excellent vision in suitable eyes. The differences are more subtle than the internet suggests.

Dry eye: creating a LASIK flap cuts more of the fine corneal nerves that drive tear production, so temporary dryness after LASIK is common for a few months. SMILE disturbs fewer of these nerves, and in my experience patients who already have borderline dry eyes often do better with it. If your eyes are already dry, we treat that first — do read about dry eye if this sounds like you.

The flap question: a LASIK flap heals securely, but it remains a structural feature of the eye. For people in contact sports, martial arts, boxing, or physically rough occupations, the flapless nature of SMILE removes even the small theoretical risk of flap displacement from a direct blow. For an office-goer, this difference rarely matters.

Speed of visual recovery: LASIK is typically a little faster to crisp vision — often by the next day. SMILE vision is good early but can take a few days longer to sharpen fully. Both settle to comparable outcomes.

Who tends to suit which

Broadly, and only broadly:

• Higher minus powers are often handled elegantly by SMILE, because it removes tissue without a flap and preserves more of the cornea’s front strength.
• LASIK covers a wider range overall, including higher cylinder and plus powers where SMILE has limits.
• Thin corneas may not safely allow either. Every laser procedure removes tissue, and there is a minimum safe thickness we will not cross — this is non-negotiable, because crossing it risks weakening the cornea permanently. For genuinely thin or borderline corneas, an ICL — a lens implanted inside the eye, removing no tissue at all — is often the better and safer answer.
• Certain corneal shapes suggest early keratoconus, a weakening condition in which laser surgery must not be done at all. Detecting this is one of the most important jobs of the pre-operative scans — you can read more on our keratoconus page.

The honest point

Here is what I want you to take away. The choice between LASIK and SMILE is not like choosing between two phones. It is a medical decision made from measurements: your corneal thickness, its shape and strength on tomography, your exact power and its stability, your tear film, your pupil size, your age and your lifestyle.

That is why we do a detailed suitability assessment before any discussion of “which one.” Sometimes the tests say both are fine, and then your lifestyle genuinely gets a vote. Sometimes they clearly favour one. And sometimes — and I say this to patients plainly — they say neither, and we look at ICL or simply better glasses or lenses. Since I began practising in 2001, some of my most satisfied patients are the ones I advised not to have laser surgery.

Come in with an open mind, get the scans done, and let the numbers guide us. The right procedure is the one your eyes qualify for.

Wondering which procedure your eyes actually qualify for? Compare LASIK, SMILE and ICL or book a suitability assessment — the surgeon who tests you is the one who operates.