Who Is a Candidate for ReLEx SMILE? Prescription Range, Corneal Maps and Tear Film

The glasses go on the nightstand and, for a moment before sleep, the room softens into shapes. That small blur is where most of these stories start: a swimmer who cannot see the lane markers, a new parent who fumbles for frames at three in the morning, a hiker tired of fogged lenses on cold ridges. Sooner or later, someone in a waiting room asks the question that brought you here: could I be a candidate for SMILE?

Small incision lenticule extraction, usually shortened to SMILE, is one of three main laser procedures for reshaping the cornea, and smile eye surgery candidacy is decided less by enthusiasm than by measurements. Three sets of numbers do most of the work: your prescription and how long it has held still, the maps of your cornea’s shape and thickness, and the state of your tear film.

This explainer walks through each of those, what surgeons are actually looking for, and the honest reasons people are told to wait or to consider something else.

What is SMILE, and how does it actually work?

The cornea is the clear, dome-shaped window at the front of the eye, and it does most of the eye’s focusing. When the dome is a little too curved for the length of the eye, distant light lands in front of the retina instead of on it. That is nearsightedness, also called myopia. Every laser vision procedure works on the same idea: change the curve of the cornea by a precise amount so light lands where it should.

SMILE does that from the inside. A femtosecond laser, which fires pulses lasting a millionth of a billionth of a second, is focused a set depth into the cornea. It creates a thin, lens-shaped disc of tissue called a lenticule, sealed within the corneal layers. The same laser then cuts a small opening at the edge of the cornea, only a few millimeters wide. Through that opening, the surgeon gently loosens and removes the lenticule. With the disc gone, the front surface settles into a flatter curve, and the nearsightedness is reduced.

Two things are different from LASIK. There is no hinged flap lifted off the surface, and there is no second laser. LASIK uses a femtosecond laser or a blade to create a flap, lifts it, reshapes the exposed tissue with an excimer laser, and lays the flap back down. PRK skips the flap entirely and reshapes the surface after the thin outer skin of the cornea is removed. Mayo Clinic describes the laser reshaping step in LASIK as typically lasting less than a minute per eye, with the appointment measured in minutes rather than hours, and the SMILE experience is similar in scale.

Numbing drops, a suction ring to hold the eye still, and a blinking light to fixate on are the ordinary parts of the day. The hard work happens weeks before, in the exam room.

SMILE eye surgery candidacy starts with a stable prescription

Surgeons like to say they can only correct the prescription you have on the day, not the one you will have in five years. That is why stability comes before everything else. Mayo Clinic advises that a person considering LASIK should have had a stable prescription for at least a year, and the same logic applies to any procedure that permanently reshapes the cornea. If your nearsightedness is still creeping up, the lenticule removed today will be the wrong size for the eye you have later.

Stability is usually judged from your old glasses or contact lens prescriptions, so bring them, even the ones in a drawer. A change in sphere or cylinder from one year to the next that a clinician considers small is treated differently from a steady climb. Refraction is the test where you read letters through different lenses; expect it to be repeated, sometimes with dilating drops that relax the focusing muscle so the true, unforced prescription shows.

Contact lenses can quietly fake instability. Soft lenses mold the cornea a little, and rigid lenses mold it a lot. Clinics ask people to stop wearing lenses for a period before measurements so the cornea returns to its natural shape; your surgeon sets the timing based on the lens type, and it can be longer for rigid lenses. Measurements taken on a lens-warped cornea can give a false reading of both prescription and shape.

Life stage matters too. Pregnancy and breastfeeding shift fluid balance and hormone levels in ways that can change the cornea and the prescription, which is why most surgeons defer until a person has finished nursing and the refraction has settled again.

Which prescription range can SMILE treat?

SMILE was developed for nearsightedness, and that remains its home territory. It also treats the kind of astigmatism that usually travels with myopia; astigmatism means the cornea is shaped more like the back of a spoon than a soup bowl, so light focuses unevenly. The lenticule can be designed with an oval, tilted shape to correct that as well.

The precise upper and lower limits depend on the laser platform, the regulatory approval in your country, and the surgeon’s own comfort, so the honest answer to “what range?” is: ask which range your surgeon’s system is licensed for and how your numbers fit within it. Two general patterns hold across most practices.

Very low prescriptions are sometimes a poorer match, because the lenticule becomes thin and fragile and harder to remove cleanly. Very high prescriptions demand a thick lenticule, which eats into corneal thickness and pushes against the safety margins discussed in the corneal maps section below. Between those edges sits the range most surgeons consider comfortable.

Farsightedness, where the eye is too short and near objects blur first, is a different problem, and SMILE for farsightedness is not routinely available in the United States. Presbyopia, the age-related loss of near focus that sends people to reading glasses in their forties, is not something SMILE fixes at all; the procedure changes the cornea, not the stiffening lens inside the eye. Someone in their fifties who has SMILE for distance will still need readers. The National Eye Institute’s overview of refractive errors is a useful primer on how these conditions differ.

Why age matters for smile eye surgery candidacy

There is no upper age limit written into SMILE, but there is a lower one, and it is less about a birthday than about biology. Nearsightedness tends to progress through the teens and often into the early twenties as the eye finishes growing. The NHS notes that laser eye surgery is generally not offered to people under 21 because eyesight may still be changing, and many surgeons in other countries set their threshold at 18 combined with proof of stability.

At the other end of life, the question flips from stability to expectations. A 45-year-old with mild nearsightedness may currently enjoy an accidental gift: taking off the distance glasses makes reading easy. Fully correcting the distance vision removes that gift, and reading glasses arrive on schedule. Some surgeons offer a deliberate small undercorrection in one eye, sometimes called monovision, so one eye favors distance and the other favors near. It suits some people and irritates others, and a trial with contact lenses before committing is a common recommendation.

Past the late fifties and sixties, the lens inside the eye begins to yellow and cloud. Early cataract, which is clouding of that lens, changes the prescription on its own and makes laser correction of the cornea a poor investment of tissue; cataract surgery, which replaces the lens, can correct the nearsightedness at the same time. A surgeon who spots early lens changes on the slit lamp exam, the microscope used to look inside the eye, may steer the conversation there instead.

Age, in other words, is a proxy. What the team really wants to know is whether the eye is finished changing and what it will need in the next two decades.

What the corneal maps are looking for

If the prescription is the first gate, the corneal maps are the second, and they are where most surprises happen. Two instruments do the heavy lifting. Corneal topography maps the curvature of the front surface, producing a color picture much like a weather map, with warm colors where the cornea is steeper and cool colors where it is flatter. Corneal tomography goes further, measuring the back surface and the thickness at thousands of points to build a three-dimensional model.

A healthy cornea looks symmetric on these maps, a little steeper in the center and gently flattening toward the edges. What the surgeon is hunting for is asymmetry: a steep patch below the center, a back surface that bulges forward, a thinnest point sitting away from the middle. Those patterns can be the earliest whisper of keratoconus, a condition in which the cornea thins and bulges into a cone shape. Mayo Clinic describes keratoconus as usually beginning in the teens to early twenties and progressing slowly for a decade or more, which means a 22-year-old with a subtly irregular map may have disease that has not yet declared itself.

This matters because removing tissue from a cornea that is already weakening can accelerate the bulging, a complication called ectasia. Screening software compares your maps against databases of normal and keratoconic eyes and flags eyes that sit in between. Many clinics also perform epithelial mapping, which measures the thickness of the cornea’s outer skin layer; the epithelium thins over a hidden cone as it tries to smooth the surface, sometimes revealing what the curvature map hides.

Borderline maps are the most common reason a person is asked to wait, repeat the scans in several months, or choose a different route.

Corneal thickness: the margin your surgeon protects

Pachymetry is the measurement of corneal thickness, and it is the number surgeons guard most jealously. Every diopter of correction requires removing a slice of tissue; the higher the prescription, the thicker the lenticule. Subtract that from your starting thickness, subtract the cap of tissue that stays above it, and what remains is the residual stromal bed, the untouched structural layer holding the cornea’s shape.

Surgeons set a floor for that bed. Go below it and the cornea can slowly give way under normal eye pressure, the ectasia described above. Where exactly the floor sits varies between surgeons and with the individual map; a thin cornea with a perfectly regular shape is treated differently from a thick one with an odd back surface. Because SMILE leaves the front layers largely intact, some surgeons argue it preserves more biomechanical strength than a flap procedure at the same correction, though how much that matters clinically is still being studied and should not be presented as settled.

Thickness also interacts with pupil size, which is measured in dim light. Large pupils that expand beyond the treated zone can let unfocused light in at night, producing halos around headlights. A wider treatment zone reduces that risk but costs more tissue. A thin cornea and large pupils together may push a person toward PRK, which does not create a cap or flap, or toward an implantable lens, a small corrective lens placed inside the eye that removes no cornea at all.

Ask to see your own numbers. A good consultation shows you the thickness map, points to the thinnest spot, and explains the arithmetic. The decision belongs to the treating team, but understanding the margin helps you understand why they say yes, wait, or no.

Tear film: why dry eyes can pause the plan

The tear film is the thin liquid coat that smooths the front of the eye, and it is a genuine optical surface; when it breaks up or thins, vision blurs and letters ghost. The National Eye Institute describes dry eye as a common condition in which the eyes do not make enough tears or the tears evaporate too quickly, and it is more frequent in older adults, in women, and in long-term contact lens wearers, which describes a large share of people seeking laser vision correction.

All corneal laser procedures cut some of the fine nerves in the cornea that signal the eye to blink and produce tears. Mayo Clinic notes that LASIK causes a temporary decrease in tear production and that dry eye is common for roughly the first six months afterward. SMILE severs fewer of these nerves because the small opening replaces a flap that circles most of the cornea, and several comparative studies report fewer dry eye symptoms in the early months after SMILE. Longer-term differences appear smaller, and the studies vary in design, so the fair summary is that SMILE may be gentler on tear film early on, not that it is immune.

Before surgery, the team measures the tear film in several ways: how quickly the tear layer breaks up after a blink, how much tear the eye produces on a small paper strip, how concentrated the tears are, and how healthy the oil glands along the eyelid margins look. Signs of poor lid oil, inflammation, or a rapidly breaking tear layer usually trigger a period of treatment first, with lubricants, lid hygiene, or anti-inflammatory drops chosen by the ophthalmologist, followed by remeasurement. Operating on an untreated dry eye tends to make a mild problem worse and a good result blurrier.

Who is usually a good fit, and who is asked to wait

Put the pieces together and a picture of the usual candidate emerges: an adult past the early twenties whose glasses prescription has not changed meaningfully for at least a year, with nearsightedness within the range the surgeon’s platform treats, astigmatism that is regular rather than lopsided, corneal maps that look symmetric front and back, enough thickness to leave a comfortable residual bed, a healthy or well-controlled tear film, and no active eye disease. Realistic expectations complete the list; the goal is reduced dependence on glasses, and the treating team will describe what is likely for your numbers, not what is guaranteed.

A separate group is told “not yet” rather than “no.” People in this group are often surprised and sometimes frustrated, but the reasons are mostly about time:

• A prescription that changed at the last visit, with a repeat refraction planned after several months.
• Current pregnancy or breastfeeding, with the plan resuming once the refraction has settled afterward.
• Untreated dry eye or eyelid gland disease, with a treatment course and remeasurement first.
• Recent contact lens wear that has not been paused long enough for the cornea to return to its natural shape.
• Corneal maps that are borderline rather than clearly abnormal, where repeat scans months apart can show whether anything is progressing.
• An eye infection, recent eye injury, or a flare of a skin or inflammatory condition affecting the eyelids.
• A recent change in a medicine known to affect healing or the eye surface, which the surgeon will want reviewed with the prescribing clinician.

Waiting is not a consolation prize. In the borderline cornea especially, the passage of time is itself a diagnostic test, and it costs nothing but patience.

Who is not a candidate for SMILE at all?

Some findings close the door on SMILE, and often on LASIK and PRK as well. Keratoconus or a clearly suspicious corneal map is the most important, because thinning an already weakening cornea risks ectasia. A cornea too thin to leave an adequate residual bed for the prescription involved is another. Farsightedness is not treated with SMILE in most settings, and presbyopia alone is not a reason for any corneal laser procedure.

Beyond the cornea, surgeons look at the whole eye and the whole person. A cataract that already affects vision points toward lens surgery instead. Uncontrolled glaucoma, active retinal disease, significant corneal scarring, or a history of certain corneal infections can each rule the procedure out. Severe dry eye that has not responded to treatment is a contraindication rather than a delay.

Systemic conditions matter because the cornea has to heal. Mayo Clinic lists autoimmune disorders such as rheumatoid arthritis, immunodeficiency states, and diabetes with poor control as conditions that may make laser vision correction less safe, and many surgeons treat uncontrolled autoimmune disease as a firm no. Conditions that affect collagen or wound healing fall into the same category.

SMILE also has practical limits that LASIK does not share. Because the correction is built into a single lenticule, small enhancements later are more complicated; there is no flap to lift, so a touch-up usually means a surface laser procedure instead. Someone whose prescription is likely to need fine-tuning may be steered elsewhere for that reason alone. And a person who cannot keep the eye still under a suction ring, or who is very anxious about the sensation, may be better served by a different approach.

None of these is a judgment about you. Each is a statement about tissue and risk, and a good surgeon will explain which applies and what the alternatives are.

SMILE vs LASIK vs PRK: how the options compare

People searching “smile vs lasik” usually want a verdict, and the honest one is that these are three tools for the same job, each with a slightly different balance of strengths. The table summarizes the mechanical differences that shape candidacy; it does not rank them, because the right choice depends on the measurements discussed above.

Feature	SMILE	LASIK	PRK
Lasers used	Femtosecond only	Femtosecond or blade for the flap, excimer for reshaping	Excimer only
Access to tissue	Small edge opening, lenticule removed from inside	Hinged flap lifted and replaced	Outer skin layer removed, regrows
Prescriptions treated	Nearsightedness and astigmatism	Nearsightedness, farsightedness, astigmatism	Nearsightedness, farsightedness, astigmatism
Flap-related risks	None (no flap)	Flap wrinkles, dislocation, growth of cells under flap	None (no flap)
Early comfort and vision	Mild discomfort, vision clears over days	Mild discomfort, vision often clear within a day	More discomfort, vision clears over days to weeks
Retreatment if needed	Usually a surface laser procedure	Flap can be relifted	Repeat surface procedure
Often considered when	Dry eye tendency, contact sports, active lifestyles	Farsightedness, fastest visual recovery wanted	Thin cornea, irregular surface, flap unsuitable

A fourth option sits off the table: a phakic intraocular lens, a thin corrective lens implanted inside the eye in front of the natural lens. It removes no corneal tissue and is often discussed with people whose prescriptions are too high or corneas too thin for any laser procedure. The NHS overview of laser and lens surgery for eyesight is a neutral place to read about how these alternatives differ.

Is SMILE riskier than LASIK?

The short answer is that the two procedures carry different risks rather than clearly more or less, and both are considered low-risk when done on well-selected eyes. The differences come straight from the mechanics.

LASIK’s characteristic risks belong to the flap. Mayo Clinic lists flap problems such as wrinkling, infection, or excess tearing, along with cells growing underneath the flap, as complications specific to that design. A flap also creates a permanent plane of weakness, which is why people who box or play rugby are sometimes steered away from it. SMILE has no flap, so those risks disappear.

SMILE’s characteristic risks belong to the lenticule and the small opening. The disc must be separated and removed intact; a torn lenticule, a fragment left behind, or difficulty finding the plane can leave the surface slightly irregular. Suction loss during the laser pass, when the eye moves and the ring releases, is uncommon but requires the surgeon to decide whether to redock or convert to a different procedure. Because SMILE relies on a single laser and a more tactile removal step, surgeon experience is often cited as mattering more in the early learning period.

Risks the two share include dry eye, glare and halos at night, under- or overcorrection, regression of effect, and, rarely, ectasia or vision-threatening infection. Mayo Clinic notes that dry eye and night glare are among the more common side effects after laser vision correction and usually improve over months.

Systematic reviews comparing the procedures generally report similar visual outcomes, with some suggesting an early advantage for SMILE in dry eye symptoms and for LASIK in speed of visual recovery, and the quality of the underlying trials is mixed. What the evidence supports is a choice based on your anatomy and lifestyle, not on a blanket claim that one is safer.

What the first days and weeks usually look like

Questions about smile eye surgery recovery time are really questions about two clocks: the one for comfort and the one for vision. Immediately after the procedure, most people describe a gritty, watery, light-sensitive eye for several hours, similar to having worn contact lenses too long. Vision is typically hazy that first evening, and many people notice it sharpen over the following days rather than overnight, which is a genuine difference from LASIK, where Mayo Clinic notes vision is often clear by the next morning.

Drops are the routine for the first weeks: an antibiotic to protect against infection while the small opening seals, an anti-inflammatory to calm the healing response, and lubricants for comfort. Your surgeon sets the schedule and the duration; they are not the same for every eye.

Most clinics ask you to avoid rubbing the eye, to skip swimming and hot tubs for a period, to keep makeup and dusty environments away from the eye at first, and to wear the shields provided while sleeping for the first nights. Screen work is usually fine once comfortable, with frequent blink breaks because concentration reduces blinking and dries the surface.

The vision clock runs longer than people expect. Mayo Clinic advises that after laser vision correction it can take two to three months for the eye to heal fully and vision to stabilize, and early fluctuation, especially between morning and evening, is normal in that window. Follow-up visits are typically scheduled within the first day or two, again at a few weeks, and again at a few months, so the team can track the tear film, the corneal surface, and the refraction. Any decision about enhancement waits until the numbers have held steady.

Recovery is not a sprint. If you have a wedding, exam, or long-haul flight coming, tell the team when, so the timing can be planned around it.

What people often get wrong

Myths gather around any procedure that involves lasers and eyes. A few deserve correcting.

“SMILE is the newest, so it must be the best.” Newer means more recently developed, not superior. The evidence shows broadly similar visual results across SMILE, LASIK, and PRK in well-chosen eyes, with trade-offs in comfort, recovery speed, and retreatment options. The best procedure is the one your anatomy fits.

“If I qualify for LASIK, I qualify for SMILE.” Not necessarily. Farsighted people qualify for LASIK but not SMILE; very low prescriptions may suit LASIK better; and a surgeon may prefer a flap for someone likely to need fine-tuning. The reverse is also true, since some dry-eye-prone or contact-sport patients are steered toward SMILE.

“Laser surgery means I will never need glasses again.” It reduces dependence for distance vision. Presbyopia will still bring reading glasses in mid-life, and a small residual prescription can remain. No reputable team promises a specific outcome.

“Dry eye after surgery means something went wrong.” Temporary dryness is an expected part of corneal healing, common in the first months after any laser vision correction according to Mayo Clinic, and it usually eases. Persistent or worsening dryness is a reason to be seen, not proof of error.

“A celebrity had it, so it is right for me.” Public figures’ medical decisions are reported secondhand and rarely include their corneal maps. Their eyes are not yours.

“Being told to wait means I have been rejected.” Waiting is often the safest, most evidence-based recommendation, especially for a borderline map or an unsettled prescription. It preserves your options rather than closing them.

Questions to ask your care team

A consultation is a two-way exam, and the questions you bring shape how well you understand the answer. These are the ones worth writing down.

• How stable has my prescription been across the records you reviewed, and what would you consider a meaningful change?
• Which prescription range does your laser platform treat for SMILE, and where do my numbers fall within it?
• Can you show me my corneal topography and tomography maps and explain what the screening software flagged, if anything?
• What is my corneal thickness, how much tissue would this correction remove, and what residual bed would remain?
• What did my tear film tests show, and should anything be treated before we schedule surgery?
• Given my age, what should I expect about reading vision in the next decade, and is monovision worth a contact lens trial?
• For my eyes specifically, why SMILE rather than LASIK, PRK, or an implantable lens, and what would change your recommendation?
• What are the specific risks for my anatomy, including night vision if my pupils are large?
• If an enhancement were needed later, how would that be done after SMILE, and how would you decide the timing?
• How many follow-up visits are planned, over what period, and who do I call after hours?
• Which of my current medicines or health conditions affect healing, and do you need to speak with my other clinicians?

Notice what is missing: nothing here asks the surgeon to rank themselves against others or to promise a result. Those answers tell you little. The answers that matter describe your tissue, your risk, and your plan, and a team that gives them plainly is showing you how it will treat you afterward.

When to call your doctor

Most recovery after SMILE is uneventful, and the surgical team will tell you what ordinary healing feels like. Some signs are not ordinary and warrant a same-day call, or emergency care if the clinic is closed.

• Pain that is increasing rather than easing, especially after the first day or two, or pain that drops do not relieve.
• Vision that was improving and then suddenly becomes worse, hazier, or develops a new dark curtain or shadow.
• Marked redness spreading across the white of the eye, thick discharge, or the eyelid becoming swollen and hot.
• Extreme sensitivity to light that is new or worsening after the early period.
• A sensation that something is stuck in the eye that persists rather than fades.
• A direct blow to the eye or a hard rub while the surface is still healing.
• A sudden shower of new floaters or flashes of light, which are not typical of corneal healing and need prompt assessment.

Mayo Clinic notes that infection and inflammation after laser vision correction are rare but can threaten sight, and early treatment is what protects the outcome. Do not wait for a scheduled appointment if something feels wrong; the team would rather see a false alarm than a late complication.

Between visits, milder concerns still deserve a message: dryness that is not improving with the prescribed lubricants, night halos that interfere with driving, or fluctuating vision that has not steadied within the timeline the team described. These are common, manageable, and easier to address early. Whatever the symptom, decisions about drops, follow-up, or any further treatment rest with the surgeon who knows your maps, your tear film, and your eye.

Frequently asked questions

How do I qualify for SMILE eye surgery?

You qualify through measurements, not by asking. Surgeons look for an adult with nearsightedness, with or without astigmatism, whose prescription has been stable for at least a year, corneal maps that are symmetric with adequate thickness, a healthy tear film, and no active eye or uncontrolled systemic disease. A full consultation with topography, tomography, pachymetry, tear tests, and a dilated exam decides it, and the surgeon makes the final call.

Who is not a candidate for SMILE?

People with keratoconus or a suspicious corneal map, corneas too thin for their prescription, unstable or farsighted prescriptions, cataract affecting vision, uncontrolled glaucoma or retinal disease, significant corneal scarring, severe untreated dry eye, or uncontrolled autoimmune conditions are usually not candidates. Pregnancy, breastfeeding, and recent contact lens wear are reasons to wait rather than firm exclusions. Your surgeon will explain which applies and what alternatives exist.

What are the smile eye surgery requirements for age?

There is no formal upper age limit, but the eye must have finished changing. The NHS notes laser eye surgery is generally not offered to people under 21 because eyesight may still be changing, and many surgeons elsewhere accept adults from 18 with documented stability. Older adults are assessed for early cataract and counseled that reading glasses will still be needed as presbyopia develops.

Is SMILE riskier than LASIK?

Neither is clearly riskier; they carry different risks. LASIK has flap-specific complications such as wrinkling or cells growing beneath the flap, which SMILE avoids. SMILE has lenticule-specific risks, including a torn or incomplete lenticule and suction loss during the laser pass. Both share dry eye, night glare, and small over- or undercorrections. Systematic reviews report broadly similar visual outcomes in well-selected eyes.

What eye surgery did Taylor Swift get?

Media reports described her having laser vision correction, widely reported as LASIK, based on a televised anecdote rather than any medical record. Whatever a public figure chose says nothing about your eyes, because candidacy depends on your prescription, corneal maps, and tear film. Treat celebrity stories as conversation starters, not evidence, and let a full examination guide your decision.

What is the difference in smile vs lasik for dry eye?

SMILE cuts fewer corneal nerves because its small opening replaces a flap that circles most of the cornea, and several comparative studies report fewer dry eye symptoms in the early months after SMILE. Differences appear smaller by a year, and study quality varies. Mayo Clinic notes dry eye is common for about the first six months after LASIK, so people with a dry eye tendency are often assessed carefully for either procedure.

How long is smile eye surgery recovery time?

Comfort usually returns within a few days, while vision sharpens over days rather than overnight and can fluctuate for weeks. Mayo Clinic advises that after laser vision correction it can take two to three months for the eye to heal fully and vision to stabilize. Follow-up visits are typically spread across that period, and any enhancement decision waits until the prescription has held steady.

Can SMILE treat farsightedness or reading vision?

SMILE is designed for nearsightedness and astigmatism, and it is not routinely available for farsightedness in the United States. It does not treat presbyopia, the age-related loss of near focus, because that comes from the stiffening lens inside the eye rather than the cornea. People in their forties and beyond will still need reading glasses after SMILE unless a monovision approach is planned.

Why did my surgeon ask me to stop contact lenses before the consultation?

Contact lenses mold the cornea, soft lenses slightly and rigid lenses considerably, which distorts both the measured prescription and the corneal maps. Pausing lenses lets the cornea return to its natural shape so the surgeon sees the true numbers. The required break depends on lens type and is set by your clinic; measuring a lens-warped cornea risks planning the wrong correction or missing an irregular shape.

What happens if I need a touch-up after SMILE?

Enhancements after SMILE are possible but handled differently from LASIK, because there is no flap to lift. Most surgeons perform a surface laser procedure such as PRK over the treated area once the prescription has been stable for months. Because retreatment is less straightforward, someone whose numbers suggest a likely need for fine-tuning may be advised toward a different procedure from the start.

References

• NHS: Laser eye surgery and lens surgery
• National Eye Institute (NIH): Refractive errors
• National Eye Institute (NIH): Dry eye

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.