Quick Answer
LASIK and SMILE are both laser vision correction procedures that reduce or eliminate the need for glasses. LASIK creates a corneal flap and removes tissue with an excimer laser; SMILE uses a femtosecond laser to extract a small disc of corneal tissue through a tiny incision — no flap required. SMILE may produce less short-term dry eye. LASIK has more robust long-term outcomes data, treats a wider prescription range, and allows enhancement surgery more easily. Both achieve comparable final visual acuity.
Detailed Explanation
SMILE (Small Incision Lenticule Extraction) has been available in the United States since its FDA approval in 2016 and has been performed globally since 2011. It represents a genuine procedural innovation rather than a marketing rebrand — the technique is meaningfully different from LASIK, and understanding the differences helps patients make an informed choice.
How each procedure works
LASIK: 1. A femtosecond laser creates a corneal flap (approximately 100–120 microns thick) 2. The flap is lifted, exposing the corneal stroma beneath 3. An excimer laser reshapes the stroma by removing tissue in a precise pattern 4. The flap is repositioned and adheres naturally — no sutures
SMILE: 1. A femtosecond laser creates a small disc of corneal tissue (the “lenticule”) at a defined depth within the stroma — without creating a full flap 2. The same femtosecond laser creates a small incision (2–4 mm, vs. LASIK’s 20+ mm flap edge) 3. The surgeon manually extracts the lenticule through this small incision using specialized instruments 4. The cornea retains its structural integrity without a full surface cut
Key clinical differences
| Feature | LASIK | SMILE | |—|—|—| | Flap creation | Yes (full surface cut) | No (small incision only) | | Lasers used | Two (femtosecond + excimer) | One (femtosecond only) | | Procedure time | 15–20 min both eyes | 15–25 min both eyes | | Myopia range | Up to approximately -11.00 D | FDA-approved up to -10.00 D | | Astigmatism treatment | Up to -6.00 D (LASIK) | Up to -3.00 D (FDA-labeled SMILE) | | Hyperopia treatment | Yes | Not currently FDA-approved | | Dry eye risk (short-term) | Higher | Lower (fewer corneal nerves cut) | | Visual recovery speed | Faster (often 20/20 next day) | Slightly slower (1–3 days to peak clarity for some) | | Enhancement surgery | Easier (flap re-lift) | More complex (PRK over SMILE site typically required) | | Long-term data availability | 25+ years | 10–12 years widespread clinical use |
Dry eye: SMILE’s primary clinical advantage
The most clinically significant difference between the two procedures is post-operative dry eye. LASIK’s flap creation severs more sub-basal corneal nerve fibers than SMILE’s small incision. These nerves regulate the blink reflex and tear secretion signaling. With LASIK, more nerves are disrupted, and recovery of corneal sensation takes longer — contributing to dry eye symptoms in the weeks to months post-operatively.
SMILE, by limiting the incision to 2–4 mm, preserves a larger proportion of sub-basal nerves. Clinical studies comparing both procedures consistently show lower short-term dry eye rates and faster return of corneal sensitivity with SMILE. For patients with any pre-existing dry eye tendency, this is a meaningful consideration.
By approximately 6–12 months, dry eye rates equalize between the two procedures in most published studies. The difference is primarily in the first 3–6 months.
Visual outcomes comparison
Both procedures achieve comparable visual acuity outcomes in peer-reviewed comparative studies. At 12 months post-operatively, the percentage of patients achieving 20/20 or better uncorrected vision is statistically similar between LASIK (particularly topography-guided LASIK) and SMILE.
Some studies suggest topography-guided LASIK (Contoura) achieves marginally superior contrast sensitivity and night vision outcomes compared to first-generation SMILE, due to the ability to optimize corneal asphericity with the excimer laser. Second-generation SMILE (SMILE Pro) addresses some of these optical limitations.
Enhancement after SMILE
This is an important practical consideration. LASIK flap re-lift allows straightforward retreatment years after the original procedure. SMILE does not create a flap, so enhancement requires either:
- Converting to a LASIK flap technique (though no prior flap exists)
- Performing PRK (surface ablation) over the SMILE site
PRK enhancement is effective but involves a longer recovery than LASIK flap re-lift. For patients considering a procedure with a higher probability of needing enhancement — higher prescriptions, younger patients with longer projected wear — this is worth factoring into the decision.
Prescription range limitations
SMILE’s FDA approval currently covers myopia up to -10.00 D with up to -3.00 D of astigmatism. LASIK covers a wider range. Patients with hyperopia (farsightedness) are not currently candidates for SMILE; LASIK remains their laser surgery option.
LASIK Surgery Awards evaluates practices that offer both LASIK and SMILE, recognizing that the best outcome depends on matching the right technology to the right patient — not defaulting to one approach for all patients.
Important Considerations
SMILE is not universally superior to LASIK. Marketing materials for SMILE sometimes imply a categorical improvement. The clinical evidence is more nuanced: each has advantages and limitations. The best procedure for you depends on your anatomy, prescription, dry eye baseline, and preference.
Surgeon SMILE experience matters significantly. SMILE requires manual lenticule extraction — a tactile skill that has a learning curve distinct from LASIK. Early in a surgeon’s SMILE experience, extraction can be more challenging. A surgeon with 500+ SMILE cases is meaningfully different from one who has performed 50.
LASIK’s outcomes data are deeper. 25-year follow-up studies on LASIK patients provide reassurance about long-term corneal stability. SMILE’s oldest large-cohort data is 10–12 years. This is not necessarily a reason to avoid SMILE — it is a reason to acknowledge the asymmetry in evidence base.
What to Do Next
1. Ask your surgeon whether you are a candidate for both procedures and what they would recommend for your specific anatomy and prescription. 2. If dry eye is a significant concern, SMILE is worth a detailed conversation. 3. Ask about the surgeon’s SMILE volume if you are interested in that procedure — experience matters here more than with LASIK.
For a look at how newer technologies compare to the current standard, see Should I Get LASIK or Wait for Better Technology?.
Related Questions
Want to understand the safety profile of LASIK specifically? Read Is LASIK Eye Surgery Safe? for a comprehensive review of outcomes data.
Wondering about LASIK side effects like dry eye and whether SMILE is genuinely better? See What Are the Side Effects of LASIK? for a detailed breakdown.
Comparing the technology used across different practices? Read What to Look for in a LASIK Surgeon to understand how to evaluate technology investment.