Trans PRK, LASIK, and SMILE are all advanced laser eye surgeries, but each has unique strengths, risks, and recovery experiences.
If you’re considering vision correction, understanding how these procedures differ will help you make the best choice for your eyes, lifestyle, and long-term vision goals.
This blog compares Trans PRK, LASIK, and SMILE in detail—explaining how each works, who they suit, recovery timelines, and what to expect—so you can make an informed decision with your eye doctor.
What Are Trans PRK, LASIK, and SMILE?
Trans PRK: No-Touch, Flapless Surface Laser
Trans PRK (Transepithelial Photorefractive Keratectomy) is a no-touch laser eye surgery that removes the corneal epithelium with a laser and then reshapes the cornea to correct vision. It’s entirely flapless, making it ideal for patients with thin or irregular corneas and those with active lifestyles who want to avoid flap complications.
LASIK: Flap-Based, Fast-Recovery Laser Surgery
LASIK (Laser-Assisted In Situ Keratomileusis) involves creating a thin corneal flap with a microkeratome or femtosecond laser. Next, the excimer laser reshapes the corneal tissue underneath. LASIK is known for its quick recovery and is widely used for myopia, hyperopia, and astigmatism.
SMILE: Flapless, Minimally Invasive Vision Correction
SMILE (Small Incision Lenticule Extraction) is a minimally invasive laser procedure that does not require creating a flap. It uses a femtosecond laser to create and remove a small lenticule from the cornea through a tiny incision, correcting myopia and astigmatism with minimal disruption to the eye’s surface.
Benefits, Risks, and Recovery: Side-by-Side Comparison
| Feature | Trans PRK | LASIK | SMILE |
| Flap Creation | No | Yes | No |
| Blade Used | No | Sometimes (microkeratome or femtosecond laser) | No |
| Suitable for Thin Cornea | Yes | No | Sometimes (depends on thickness and prescription) |
| Dry Eye Risk | Low | Moderate (due to flap and nerve disruption) | Low (preserves more corneal nerves) |
| Recovery Time | 1–4 weeks for functional vision; full stabilisation in 2–3 months | 1–2 days for functional vision; stable in 1–2 weeks | 2–4 days for functional vision; full recovery in weeks |
| Pain/Discomfort | Moderate (especially first 2–3 days) | Minimal | Minimal |
| Activity Restriction | 1–2 weeks | 1–2 days | 1–2 days |
| Prescription Range | Myopia up to -10D, Hyperopia up to +3D, Astigmatism up to -6D | Myopia up to -12D, Hyperopia up to +6D, Astigmatism up to -6D | Myopia up to -10D, Astigmatism up to -5D |
| Cost | Moderate | Moderate-High | Moderate-High |
| Best For | Thin/irregular corneas, athletes, dry eye patients | Fast recovery, wide prescription range | Flapless option for moderate myopia/astigmatism, low dry eye risk |
Who Is a Good Candidate for Each Procedure?
Trans PRK Candidacy
- Ideal for: Patients with thin or irregular corneas, active lifestyles (sports, high risk of trauma), or those at higher risk of dry eye or flap complications.
- Not suitable for: Very high prescriptions, unstable refraction, or active/severe ocular disease.
- Prescription range: Myopia up to -10D, hyperopia up to +3D, astigmatism up to -6D
LASIK Candidacy
- Ideal for: Patients with stable vision, adequate corneal thickness, and no contraindications like dry eye or corneal abnormalities.
- Not suitable for: Thin corneas, irregular topography, high dry eye risk, or active infections.
- Prescription range: Myopia up to -12D, hyperopia up to +6D, astigmatism up to -6D
SMILE Candidacy
- Ideal for: Patients with mild to moderate myopia and astigmatism who prefer a flapless procedure and have adequate corneal thickness.
- Not suitable for: Hyperopia, very high astigmatism, irregular corneas, or unstable vision.
- Prescription range: Myopia up to -10D, astigmatism up to -5D
How Do the Procedures Work?
Trans PRK: The No-Touch Approach
- The excimer laser simultaneously removes the corneal epithelium and reshapes the cornea in a single step.
- No blade or flap is involved, reducing risks for certain patients.
- A bandage contact lens is applied to promote healing.
- Discomfort typically peaks in the first 2–3 days, and vision gradually improves over 1–4 weeks, though full stabilisation may take up to 2–3 months.
LASIK: Flap Creation and Rapid Recovery
- A thin flap is created and lifted.
- The excimer laser reshapes the corneal tissue beneath.
- The flap is then placed back in its original position, serving as a natural bandage.
- Most patients experience clearer vision within 24–48 hours and can return to work quickly, though full visual stabilisation may take a few weeks.
SMILE: Small Incision, Less Disruption
- A femtosecond laser creates a tiny lenticule inside the corneal tissue.
- The lenticule is removed through a tiny incision (2–4 mm).
- No flap is created, which preserves more corneal nerves.
- Most patients see noticeable improvement within 2–4 days, with full recovery in several weeks.
Recovery Experience: What to Expect?
- Trans PRK: Expect mild to moderate discomfort for 2–3 days, with vision gradually improving over the next few weeks. Full stabilisation can take up to 2–3 months.
- LASIK: Most patients experience minimal discomfort and return to daily activities within a day or two. Vision typically stabilises within several weeks.
- SMILE: Recovery is quick, with most people seeing well within a few days and returning to normal routines soon after.
Benefits and Drawbacks: A Closer Look
Trans PRK
Pros:
- No flap or blade—lower risk of flap complications
- Suitable for thin or irregular corneas
- Lower risk of dry eye
- Good option for contact sports or physically demanding jobs
Cons:
- Longer initial recovery and discomfort
- Vision may fluctuate for weeks
- Risk of temporary haze (especially with higher prescriptions) or, rarely, corneal scarring
LASIK
Pros:
- Fast recovery and minimal discomfort
- High precision and predictability
- Widely available and suitable for most prescriptions
Cons:
- Flap-related complications possible
- Higher risk of dry eye, especially in predisposed individuals
- Not ideal for thin corneas or irregular topography
SMILE
Pros:
- Flapless and minimally invasive
- Lower dry eye risk than LASIK
- Small incision means less nerve disruption
Cons:
- Not recommended for hyperopia or severe astigmatism
- Slightly longer laser time than LASIK
- Slight chance of suction loss or lenticule extraction issues, though rare
How to Choose? Factors to Consider
- Corneal thickness: Thin or irregular corneas often rule out LASIK, making Trans PRK or SMILE better options.
- Prescription range: LASIK treats the widest range of prescriptions. SMILE and Trans PRK are more limited.
- Lifestyle: If you’re in contact sports or have a job with a higher risk of facial impact, flapless options like Trans PRK or SMILE reduce the chance of flap-related issues.
- Dry eye risk: If you have a history of dry eye, consider SMILE or Trans PRK.
- Recovery time: LASIK offers the fastest recovery, but SMILE is close behind. Trans PRK requires more patience but is gentler for certain eyes.
Making the Best Choice for Your Vision
Trans PRK, LASIK, and SMILE each have unique strengths and are suited to different eyes and lifestyles.
The best way to choose is to consult a qualified refractive surgeon who can assess your eyes, discuss your goals, and recommend the safest, most effective option. With the right information and expert care, you’ll be on your way to clear, comfortable vision that fits your life.
Frequently Asked Questions (FAQs)
Which procedure is the safest?
All three are considered safe when done by an experienced surgeon. The “safest” option depends on your eye structure, health, and lifestyle.
Will I need glasses after surgery?
Most people achieve clear vision without glasses, but some may need reading glasses as they age or for very fine print.
Is one procedure less painful than the others?
LASIK and SMILE usually cause minimal discomfort. Trans PRK has more discomfort in the first few days, but this is temporary.
Can I have surgery if I have dry eye?
Yes, but SMILE and Trans PRK are typically better choices if you have dry eye, since they disturb fewer corneal nerves than LASIK.
