Key points
- SMILE candidates need a prescription that hasn't changed in the last year, healthy corneas and generally good eye health (AAO).
- PRK removes a thin outer layer of corneal cells instead of making a flap. The AAO says eye pain may last 2 to 3 days.
- Phakic lenses such as the ICL are for refractive errors too large to correct safely with surgery on the cornea. The natural lens stays in place.
- Refractive lens exchange replaces the natural lens, which makes it surgery inside the eye.
Each of these procedures works differently and suits different eyes. This guide summarizes how the American Academy of Ophthalmology (AAO), the FDA and Cleveland Clinic describe them. It doesn't recommend any procedure. Only a surgeon who has examined you can say which, if any, fits your corneas and prescription.
The options at a glance
| Procedure | How it works | Candidacy notes | Recovery notes |
|---|---|---|---|
| SMILE | A suction ring flattens the cornea and a laser shapes a disc-shaped piece of tissue inside it | Stable prescription for a year, healthy corneas, generally good eye health | Ask your surgeon; the AAO page we reviewed doesn't give a timeline |
| PRK | Removes a thin outer layer of corneal cells instead of making a flap | Not for corneal scars or disease, advanced glaucoma, a vision-affecting cataract, uncontrolled diabetes, pregnancy or nursing | Eye pain 2 to 3 days; full recovery in about six weeks; stable by six months |
| ICL (phakic IOL) | A lens implanted in front of or behind the iris; the natural lens stays | Refractive errors too large to correct safely on the cornea | Ask about long-term monitoring, given the reported complications |
| Refractive lens exchange | Replaces the natural lens with an artificial one | Discussed as an option for some people who aren't LASIK candidates | Surgery inside the eye, with the risks that brings |
SMILE (small incision lenticule extraction)
The AAO describes SMILE as a newer type of laser refractive surgery. Candidates need a prescription that hasn't changed in the last year, healthy corneas and generally good eye health, and some people are not candidates.
During the procedure, the eye is numbed with drops, a suction ring flattens the cornea, and the laser shapes a disc-shaped piece of tissue inside the cornea. Questions worth asking if SMILE comes up:
- How much experience does the surgeon have with SMILE specifically?
- Why does the surgeon think SMILE suits your eyes better than LASIK or PRK?
- What does recovery look like for you, and how long does follow-up last?
PRK (photorefractive keratectomy)
PRK removes a thin outer layer of corneal cells instead of making a flap, and those cells take a few days to grow back, according to the AAO's recovery page. The AAO's PRK page says the procedure usually takes about 15 minutes and that you may have eye pain for 2 to 3 days.
People who may not be candidates include those with corneal scars or disease, advanced glaucoma, a cataract affecting vision or uncontrolled diabetes, and people who are pregnant or nursing. Listed risks include corneal scarring, infection and blindness. Cleveland Clinic says most people recover fully in about six weeks and that eyes should be stable by six months.
Because PRK works without a flap, ask your surgeon whether that difference matters for your eyes, your job or your activities. The answer should be specific to you, not a general sales point.
ICL and other phakic intraocular lenses
Phakic intraocular lenses (IOLs) are for people with refractive errors too large to correct safely with surgery on the cornea, according to the AAO. The lens is implanted in front of or behind the iris, and the eye's natural lens stays in place.
An AAO technology assessment says two phakic IOLs are FDA-approved. It reports that for myopia of –8 diopters or more, phakic IOLs may give better vision than laser surgery and be safer than refractive lens exchange. It also lists reported complications: loss of endothelial cells, cataract, secondary glaucoma, iris atrophy and dislocation from trauma.
FDA approval milestones
- 2005: Visian ICL approved for myopia (PMA P030016), according to a clinical trial protocol filed on ClinicalTrials.gov.
- 2018: Toric ICL approved, according to the same protocol.
- March 2022: EVO ICL approved for ages 21 to 45 with a refraction that has been stable for one year, according to a separate trial protocol.
You can read the EVO ICL FDA label yourself. The FDA's general advice for refractive surgery, to read the manufacturer's patient information before deciding, is a sensible habit for any implanted lens.
Refractive lens exchange (clear lens extraction)
Refractive lens exchange (RLE), also called clear lens extraction, replaces the eye's natural lens with an artificial one, according to the AAO. An older AAO EyeNet article describes RLE as an option for patients who aren't LASIK candidates. It reports that the insurer OMIC worries patients may not understand that RLE is surgery inside the eye, with the risks that brings.
If RLE comes up, ask which artificial lens would be used and why, and what the risks of surgery inside the eye are for you in particular.
Cost: what we can and can't tell you
We haven't verified current California prices for any of these procedures. An older AAO article we reviewed priced phakic lens surgery higher per eye than laser surgery, but its figures are years old, so we don't repeat them as today's prices. The FDA notes that most medical insurance does not pay for refractive surgery. When you collect quotes, ask:
- Is the quote per eye or for both eyes?
- Are lens or device costs included, or billed separately?
- How many follow-up visits are included, and over what period?
- What happens, and what does it cost, if a further procedure is needed?
Before you decide
Verify the surgeon's license with the Medical Board of California, or with the Osteopathic Medical Board of California for DOs. Our license-check guide explains the steps. The LASIK guide covers the FDA's general advice on choosing a refractive surgeon, including not choosing on cost alone.
Frequently asked questions
Is SMILE the same as LASIK?
They are different procedures. The AAO describes SMILE as a newer type of laser refractive surgery in which a laser shapes a disc-shaped piece of tissue inside the cornea. Your surgeon can explain how the difference applies to your eyes.
Why does PRK take longer to recover from?
PRK removes a thin outer layer of corneal cells instead of making a flap, and the AAO says those cells take a few days to grow back. Cleveland Clinic says most people recover fully in about six weeks.
Who is an ICL meant for?
The AAO says phakic lenses are for people with refractive errors too large to correct safely with surgery on the cornea.
Does an ICL remove my natural lens?
No. With a phakic IOL, the natural lens stays in place. Refractive lens exchange is the procedure that replaces it.
Is there an age range for EVO ICL?
Its March 2022 FDA approval covered ages 21 to 45 with a refraction stable for one year, according to a trial protocol on ClinicalTrials.gov.
Sources
- What Is Small Incision Lenticule Extraction (SMILE)? — American Academy of Ophthalmology
- Photorefractive Keratectomy (PRK) — American Academy of Ophthalmology
- Laser Surgery Recovery — American Academy of Ophthalmology
- PRK Eye Surgery — Cleveland Clinic
- Refractive Surgery Alternative Procedures — American Academy of Ophthalmology
- Phakic Intraocular Lens Implantation technology assessment — American Academy of Ophthalmology
- Trial protocol citing Visian ICL and Toric ICL approvals (NCT04283149) — ClinicalTrials.gov
- Trial protocol citing EVO ICL approval (NCT05538754) — ClinicalTrials.gov
- EVO ICL labeling (P030016/S035) — U.S. Food and Drug Administration
- Refractive Lens Exchange debate — American Academy of Ophthalmology EyeNet
- When is LASIK not for me? — U.S. Food and Drug Administration
- License Verification — Medical Board of California