Content is educational and planning-oriented. It does not replace diagnosis, treatment, or personalized medical advice from a licensed healthcare professional. Outcomes vary by individual case.
SMILE is a flap-free laser vision correction using a femtosecond laser to reshape the cornea through a small 2-3mm incision.
Candidates typically need stable myopia (-1 to -8 D) with sufficient corneal thickness and healthy ocular anatomy.
Clinical studies report 88-98% of patients achieve target refraction within 0.5-1 diopter at 3 months postoperatively.
SMILE may offer reduced dry eye symptoms compared to LASIK, though individual results vary.
Comprehensive preoperative screening by a qualified ophthalmologist is essential to determine candidacy.
Educational information only
This content is general education and does not replace evaluation by a licensed clinician. If you have symptoms, complications, or urgent concerns, seek in-person medical care.
What Is SMILE? Understanding the Procedure
SMILE (Small Incision Lenticule Extraction) represents an advancement in laser vision correction technology. Unlike traditional LASIK procedures that create a corneal flap, SMILE uses a femtosecond laser to create and extract a thin lenticule of corneal tissue through a small incision, reshaping the cornea to correct refractive error. [S1, S3]
The procedure begins with the femtosecond laser precisely creating a thin, disk-shaped lenticule within the cornea. The surgeon then extracts this lenticule through a small 2-3mm incision, effectively removing the tissue that contributes to the patient's myopia or astigmatism. This approach eliminates the need for a microkeratome or excimer laser typically used in LASIK procedures. [S1]
SMILE takes approximately 20-35 seconds of laser time per eye, with the entire procedure typically completed in under 15 minutes. The small incision size is a key distinguishing factor from LASIK, which requires creating a 20-24mm corneal flap. This smaller incision may contribute to greater corneal biomechanical stability postoperatively, as fewer corneal nerves are disrupted during the procedure. [S1]
FDA Approval Status
The procedure has received FDA approval for myopia correction ranging from -1 to -8 diopters and myopic astigmatism up to -3 diopters. Approval status and indications may vary by regulatory jurisdiction. [S1]
How SMILE Differs from LASIK
The fundamental difference between SMILE and LASIK lies in how the cornea is accessed for reshaping. In LASIK, a hinged corneal flap is created and lifted, allowing an excimer laser to ablate the underlying corneal tissue. The flap is then repositioned and heals over time, though it never fully regains its pre-surgical strength. [S1, S4]
SMILE eliminates the flap creation step entirely. Instead, the femtosecond laser creates both the lenticule and the small side incision in a single process. This approach may offer reduced risk of flap-related complications, minimal disruption to corneal nerves (which may translate to less postoperative dry eye), and preservation of more corneal biomechanical strength. [S1, S4]
However, each procedure has specific indications. SMILE is primarily approved for myopia and myopic astigmatism, while LASIK can address a broader range of refractive errors including hyperopia and higher-order aberrations. A surgeon can help determine which procedure aligns with your specific vision correction needs based on comprehensive preoperative evaluation. [S1, S4]
Learn more about other eye treatments available and how they compare. Our eye care resources provide additional context for vision correction options.
The Science Behind the Procedure
The VisuMax femtosecond laser used in SMILE procedures operates at high precision, creating photodisruption within the cornea at predetermined depths and dimensions. This laser technology allows for customizable lenticule parameters based on the patient's refractive error and corneal characteristics. [S1]
Recent clinical research comparing the newer VisuMax 800 platform to the earlier VisuMax 500 shows promising developments in laser efficiency. Studies indicate the newer platform can complete lenticule creation in approximately 10 seconds compared to 28 seconds with the previous generation, while maintaining comparable visual outcomes. This reduced procedure time may enhance patient comfort during the laser portion of the surgery. [S2]
Who Is a Good Candidate for SMILE?
Determining candidacy for SMILE requires comprehensive evaluation by a qualified ophthalmologist. Several factors influence whether this procedure is appropriate for an individual patient, and not everyone who desires vision correction will qualify for SMILE specifically. [S1]
Individual Assessment Required
Only a qualified ophthalmologist can determine your candidacy for SMILE after thorough examination. The information below provides general guidelines, not personal medical advice. Your individual circumstances may affect candidacy.
Basic Eligibility Requirements
The minimum age for SMILE candidacy is typically 22 years, with the additional requirement that the refractive prescription has remained stable for at least one year prior to the procedure. This stability requirement helps ensure that the correction applied will remain effective rather than being undermined by ongoing changes in the eye's refractive status. [S1, S4]
Regarding prescription parameters, approved indications generally include myopia from -1 to -8 diopters and myopic astigmatism up to -3 diopters. Patients with higher degrees of myopia or hyperopia may need to consider alternative procedures, as the amount of corneal tissue that can be safely removed is limited by the cornea's thickness and structural requirements. [S1, S4]
Stable general health is also important. Patients with autoimmune conditions affecting wound healing, uncontrolled diabetes, or certain connective tissue disorders may face increased risks of complications and slower healing. These conditions do not automatically disqualify someone from SMILE but require careful consideration and discussion with both the ophthalmologist and the patient's primary care provider. [S1]
Corneal Thickness and Topography Considerations
Adequate corneal thickness is one of the most critical factors in determining SMILE candidacy. The procedure requires sufficient corneal tissue to safely create and extract the lenticule while maintaining adequate residual stromal thickness for long-term corneal stability. A minimum corneal thickness of approximately 475 micrometers is typically required, with a residual stromal bed of at least 250 micrometers recommended postoperatively. [S1, S4]
Corneal topography mapping is essential to identify any irregularities or early signs of keratoconus or other corneal ectasias. Patients with forme fruste keratoconus (subclinical keratoconus) or other corneal abnormalities may not be suitable candidates for SMILE, as removing corneal tissue from an already compromised cornea could accelerate disease progression or lead to unpredictable outcomes. [S1]
The overall shape and curvature of the cornea are evaluated to ensure the eye's optical system can benefit from the correction SMILE provides. Highly irregular corneas may require alternative approaches or may not be amenable to laser vision correction at all. [S1]
Our accredited surgical facilities use advanced diagnostic technology to accurately assess corneal thickness and topography as part of the candidacy evaluation.
When SMILE May Not Be Recommended
Certain conditions and circumstances may make SMILE unsuitable or require postponement. Pregnant or nursing patients are generally advised to wait, as hormonal changes can affect corneal shape and refractive status, potentially leading to unstable outcomes. [S1]
Patients with severe dry eye syndrome may need to address this condition before proceeding with any laser vision correction, including SMILE. While SMILE typically causes less dry eye than LASIK, pre-existing severe dry eye can complicate recovery and affect final visual outcomes. [S1, S4]
Active eye infections, inflammation, or certain corneal diseases contraindicate SMILE until the condition is resolved and the eye has stabilized. Additionally, patients with cataracts, advanced glaucoma, or other significant ocular pathology may not be candidates and should discuss their specific situation with an eye care specialist. [S1]
Retinal conditions, including lattice degeneration or retinal tears, may require treatment before proceeding with SMILE. A comprehensive retinal evaluation is typically part of the preoperative assessment to identify and address any concerns that could affect surgical outcomes. [S1]
What the Evidence Shows: Outcomes and Efficacy
Clinical research on SMILE has accumulated significantly since the procedure's introduction, providing substantial data on its efficacy, safety, and long-term outcomes. Understanding this evidence base helps prospective patients make informed decisions about their vision correction options. [S1]
Clinical Efficacy and Predictability
Studies examining SMILE outcomes demonstrate high predictability in achieving target refractive correction. Clinical data indicates that 88-98% of patients achieve target refraction within 0.5-1 diopter at three months postoperatively, with stable results maintained through long-term follow-up. This level of predictability is comparable to established outcomes with LASIK for similar indications. [S1, S4]
Visual acuity outcomes following SMILE are generally favorable, with 61-96% of patients achieving uncorrected distance vision of 20/20 or better in studies. The wide range in reported outcomes reflects differences in study populations, preoperative prescription ranges, follow-up periods, and measurement methodologies across different clinical investigations. [S1, S4]
Enhancement procedures may be needed in approximately 3% of cases within two years of the original surgery. The need for enhancement varies based on initial prescription complexity, individual healing responses, and other factors. Enhancement options after SMILE are more complex than after LASIK, often requiring conversion to LASIK or surface ablation techniques rather than a simple re-treatment. [S1]
Safety Profile
The safety profile of SMILE appears comparable to LASIK based on multiple comparative studies and meta-analyses. Serious complications are relatively rare, with most adverse events being mild and self-limiting. The absence of a corneal flap eliminates flap-related complications entirely, which represents a meaningful safety advantage for patients concerned about these specific risks. [S1, S4]
Common postoperative experiences include mild irritation, light sensitivity, and visual fluctuations during the first few weeks. These symptoms typically resolve as the cornea heals and vision stabilizes. Dry eye symptoms do occur with SMILE, though research suggests they may be less frequent and less severe compared to LASIK in the early postoperative period. [S1, S4]
Long-term Data
Long-term data beyond 10 years continues to accumulate as SMILE has been performed globally since 2011. Current evidence supports durable outcomes for the majority of patients, though ongoing research continues to characterize very long-term results. Individual outcomes may vary.
Long-term Stability
Evidence suggests that SMILE provides stable refractive correction over time, with minimal regression in the majority of patients. The procedure's design, which preserves more anterior corneal tissue and maintains greater overall corneal biomechanical integrity, may contribute to this stability. [S1]
Studies tracking patients five years or more post-SMILE report maintained refractive correction in the vast majority of cases. Regression, when it occurs, is typically modest and may relate to factors such as initial prescription stability, age at surgery, and individual biological responses to the procedure. [S1, S4]
Benefits and Considerations
Understanding both the advantages and limitations of SMILE helps prospective patients weigh this option against alternative vision correction approaches.
Potential Advantages
The smaller incision in SMILE (2-3mm versus 20-24mm for LASIK) means fewer corneal nerves are disrupted during the procedure. This may translate to reduced postoperative dry eye symptoms, which is a common concern with LASIK and other flap-based procedures. For patients who experience significant dry eye with contact lens wear, this potential advantage may be particularly relevant. [S1, S4]
Corneal biomechanical stability appears better preserved with SMILE compared to LASIK. By avoiding flap creation, more of the cornea's natural strength is maintained. While the long-term clinical significance of this difference continues to be studied, it represents a theoretical advantage, particularly for patients in physically demanding occupations or those concerned about potential eye trauma. [S1, S4]
The single-laser platform of SMILE simplifies the surgical process, potentially reducing procedure time and the number of variables that could affect outcomes. Some patients appreciate the efficiency of having the entire procedure performed by one device without the need to transition between different laser systems. [S1]
Consider discussing your lifestyle, occupation, and specific vision goals with your surgeon to determine whether SMILE's advantages align with your individual needs.
Important Considerations
Visual recovery following SMILE may be slightly slower than with LASIK in the initial days and weeks. While LASIK patients often achieve functional vision within 24-48 hours, SMILE patients may experience a more gradual improvement over the first week. Most patients achieve stable vision within one to two weeks, though full stabilization may take longer in some cases. [S1, S3]
Undercorrection, particularly for astigmatism, occurs more frequently with SMILE than with LASIK in some studies. Research suggests approximately 11% of astigmatism cases may experience some degree of undercorrection, though significant residual astigmatism requiring enhancement is less common. Understanding this possibility helps set realistic expectations. [S1, S4]
The range of treatable prescriptions is narrower with SMILE compared to LASIK. Patients with higher degrees of myopia, hyperopia, or mixed astigmatism may not be candidates for SMILE and should discuss alternative procedures with their ophthalmologist. [S1]
Recovery and What to Expect
Understanding the recovery process helps patients plan appropriately and set realistic expectations for their post-SMILE experience.
Immediate Postoperative Period
Following SMILE, patients typically rest briefly at the surgical facility before being discharged with protective eyewear and detailed postoperative instructions. Most patients can return to their accommodation the same day, though someone else should arrange transportation as driving immediately after the procedure is not possible. [S1]
The first few hours after surgery may involve mild discomfort, foreign body sensation, and light sensitivity. These symptoms are normal responses to the corneal incision and typically improve significantly within the first 24 hours. Most patients report being quite comfortable by the following morning. [S1]
Vision on the first postoperative day is often described as foggy or hazy, with gradual clearing over the subsequent days. Functional vision for daily activities typically returns within the first week, though visual fluctuations and minor fluctuations in clarity may continue during the stabilization period. [S1, S3]
First Weeks of Recovery
During the first one to two weeks, patients use prescribed eye drops as directed to support healing and reduce infection risk. These typically include antibiotic drops and anti-inflammatory medications. Patients should avoid rubbing their eyes during this period to protect the healing incision. [S1]
Most patients can return to most normal activities within a few days, with the exception of swimming, hot tubs, and activities involving significant dust or debris exposure. Strenuous exercise and heavy lifting should be limited for at least one week, though walking and light activity are generally encouraged. [S1]
Dry eye symptoms may be present during the early recovery period and typically improve over weeks to months. Artificial tears can help manage temporary dryness, and patients should discuss persistent symptoms with their eye care provider. [S1, S3]
Our international patient services team can help coordinate postoperative care plans and ensure you have access to support during your recovery period.
Long-term Care
Following complete healing, routine eye care should continue as recommended by your ophthalmologist. Annual comprehensive eye examinations help monitor ocular health and detect any changes that may require attention over time. [S1]
Contact lens wear is typically not necessary following successful SMILE, as the procedure aims to reduce or eliminate dependence on corrective lenses. Some patients, particularly those with presbyopia or higher-order aberrations, may still need reading glasses or occasional distance correction for optimal vision in all conditions. [S1]
Any unusual symptoms such as persistent pain, significant vision changes, or signs of infection should prompt immediate contact with an eye care provider. While serious complications are uncommon, prompt attention to concerning symptoms helps ensure appropriate management if needed. [S1]
Taking the Next Steps
For international patients considering SMILE in Istanbul, planning involves both the medical evaluation and practical travel considerations.
Preparing for Your Consultation
Gathering your current eyeglass or contact lens prescription history provides valuable information for your preoperative evaluation. If possible, obtain records of previous eye examinations and any relevant medical history from your regular eye care provider to share with the surgical team. [S1]
Having a clear understanding of your vision correction goals helps guide the consultation discussion. Consider what activities you hope to reduce dependence on glasses or contacts for, and any specific concerns or questions you want addressed during your appointment. [S1]
Our ophthalmology team includes surgeons experienced in SMILE and other advanced vision correction procedures who can assess your candidacy and recommend the most appropriate option for your individual needs.
Questions to Ask Your Surgeon
During your consultation, asking about the surgeon's experience with SMILE specifically helps gauge expertise. Inquire about the number of SMILE procedures performed, outcomes data, and how complications are managed should they arise. [S1]
Understanding the complete fee structure, including any potential additional costs for enhancements or postoperative care, helps with financial planning. Ask what is included in the quoted price and what circumstances might incur additional charges. [S1]
Discuss the facility where the procedure would be performed, including accreditation status and emergency protocols. Knowing that the surgical center meets established standards for safety and quality provides important peace of mind. [S1]
International Patient Considerations
Planning appropriate time in Istanbul involves scheduling the initial consultation, allowing for preoperative testing, scheduling the procedure, and remaining for recommended postoperative follow-up. The exact duration varies based on individual circumstances and your surgeon's specific protocols. [S1]
Arranging accommodation that allows for rest during the initial recovery period and easy access to the surgical facility simplifies the experience. Many international patients find serviced apartments or hotels near the medical district suitable for their recovery needs. [S1]
Understanding the plan for ongoing care once you return home is important. Ask about communication protocols for questions or concerns that arise after departure and how postoperative follow-up will be coordinated with your local eye care provider. [S1]
Start Your Plan with a personalized consultation to determine if SMILE aligns with your vision correction goals.
2.Nature Scientific Reports. “Comparison of clinical outcomes following small incision lenticule extraction performed with the Visumax 800 versus Visumax 500 femtosecond laser.” 2025. Accessed 2026-02-19.https://www.nature.com/articles/s41598-025-98041-9
