SMILE and LASIK produce nearly identical visual outcomes. In comparative studies, 94% of SMILE patients and 95% of LASIK patients achieved 20/20 vision or better, with no statistically significant difference between the two. Where they diverge is in how they get there, and those differences matter depending on your eyes, your lifestyle, and your tolerance for dry eye.
How the Two Procedures Differ
Both surgeries reshape the cornea to correct your vision, but they do it in fundamentally different ways. LASIK uses two lasers: one creates a hinged flap across the cornea (about 8 mm in diameter), and a second laser reshapes the tissue underneath. The flap is then folded back into place. SMILE uses a single laser to carve a tiny disc of tissue (called a lenticule) inside the cornea, which the surgeon removes through a small incision of just 2 to 4 mm. No flap is created.
That difference in incision size is the root of nearly every practical distinction between the two procedures.
Visual Sharpness After Surgery
If your primary concern is how well you’ll see afterward, the two procedures are essentially tied. A comparative analysis of LASIK, SMILE, and PRK found no meaningful difference in the percentage of patients reaching 20/20 vision. Both procedures also produce similar levels of higher-order aberrations, the optical imperfections that cause glare and halos at night. The one exception: SMILE tends to induce slightly more vertical coma, a specific type of aberration that can subtly affect vision under certain lighting. In practice, most patients don’t notice a difference.
Dry Eye After Surgery
This is where SMILE has its clearest advantage. Because LASIK’s large flap cuts through a significant number of corneal nerves, it disrupts the feedback loop that tells your eyes to produce tears. SMILE’s smaller incision severs far fewer nerves.
A meta-analysis pooling data from multiple studies found that at six months after surgery, LASIK patients still reported significantly worse dry eye symptoms compared to their pre-surgery baseline. SMILE patients, by contrast, had returned to their pre-operative comfort levels by that same point. Objective tear film measurements also favored SMILE at every follow-up visit through six months. By 12 months, LASIK dry eye symptoms typically resolve as well, but that’s a long stretch of discomfort if you’re already prone to dry eyes.
Corneal Nerve Recovery
The nerve damage story reinforces the dry eye findings. A systematic review found that SMILE patients had significantly higher corneal nerve density at one and three months after surgery compared to LASIK patients. By six months, the two groups converged and nerve density was no longer statistically different. So SMILE doesn’t necessarily preserve more nerves long term, but it gives them a meaningful head start in healing, which translates to less dry eye during those early months.
Structural Stability and Sports
LASIK’s flap never fully bonds back to the cornea. It heals well enough for everyday life, but a direct blow to the eye can theoretically dislodge it, even years later. This is why contact sport athletes are typically advised to wait at least one month before returning to play after LASIK, with boxing and martial arts requiring a full 12 weeks.
SMILE’s flapless design eliminates that risk entirely. The small incision heals more like a sealed pocket, leaving the cornea’s structural integrity largely intact. For people who play contact sports, do martial arts, or work in environments where eye trauma is possible, this is a significant practical advantage. Recovery guidelines for SMILE generally allow a faster return to physical activity, though you should still protect your eyes during the initial healing period.
What Each Procedure Can Correct
LASIK has broader FDA-approved applications. It can correct nearsightedness, farsightedness, and astigmatism across a wide range of prescriptions. SMILE is more limited: it’s approved for myopia between -1.0 and -10.0 diopters and astigmatism up to -3.0 diopters. It is not approved for farsightedness. If you’re farsighted, SMILE is simply not an option.
LASIK also has an edge when it comes to wavefront-guided (custom) treatments, which map and correct the unique imperfections of your individual eye. SMILE does not currently offer this level of customization.
Touch-Up Rates
One study tracking 2,643 consecutive SMILE procedures found that 4.39% of patients needed a retreatment to fine-tune their results. When retreatment is needed after SMILE, it’s typically performed as a LASIK procedure on top of the original SMILE correction, which adds complexity. LASIK retreatments after an initial LASIK procedure are more straightforward since the surgeon can simply lift the existing flap. LASIK enhancement rates vary by study but generally fall in a similar range.
Where SMILE Wins
- Dry eye: Significantly less disruption to tear production, with faster return to baseline comfort
- Corneal stability: No flap means no risk of flap displacement from trauma
- Nerve recovery: Faster healing of corneal nerves in the first three months
- Active lifestyles: Better suited for contact sports, military service, or high-impact activities
Where LASIK Wins
- Broader correction range: Treats farsightedness, which SMILE cannot
- Custom treatments: Wavefront-guided options for more precise correction of individual optical imperfections
- Easier enhancements: Touch-ups are simpler when the flap can be re-lifted
- Longer track record: Decades of data and refinement compared to SMILE’s shorter history
Choosing Between the Two
For a straightforward case of nearsightedness with or without moderate astigmatism, SMILE’s advantages in dry eye and structural integrity make it a compelling choice, particularly if you have active hobbies or already experience dry eyes. For farsightedness, higher astigmatism, or cases where custom wavefront correction would make a meaningful difference, LASIK remains the better tool. In terms of the outcome that matters most to most people, how well you see afterward, the two are functionally equivalent.