You want to stop wearing glasses or contact lenses, and you are offered four acronyms. Which is right? In most cases your eyes decide, not your preference. Corneal thickness and shape, the size of your prescription, dry eye, your age and your work or sport all steer the choice. A good clinic will sometimes tell you that the procedure you asked for is not the safe one for you, or that none is.
LASIK, SMILE and PRK all reshape the cornea with a laser. They differ in how the laser reaches the tissue. ICL is different: a thin lens is placed inside the eye, in front of your natural lens, and the cornea is left alone. All four have long safety records. All four carry small risks that are permanent when they happen.
Key points
- Your corneal scans, not the brochure, determine which procedures are safe for you.
- LASIK gives the fastest recovery. PRK is slower and more uncomfortable but avoids a flap. SMILE sits between them with a small incision.
- ICL suits high prescriptions and thin corneas, and is removable, but it is surgery inside the eye.
- None of these prevents presbyopia. Most people need reading glasses from their mid 40s regardless.
- A stable prescription for at least 12 months and a thorough screening for keratoconus are essential before any of them.
How each procedure works
It helps to picture where the correction happens. Three procedures remove corneal tissue, one adds a lens. That single distinction explains most of the differences in suitability and risk.
- LASIK: A femtosecond laser creates a thin hinged flap in the cornea. An excimer laser reshapes the tissue underneath and the flap is laid back. Vision is usually functional within a day.
- SMILE: A femtosecond laser cuts a small lens-shaped disc inside the cornea, which is removed through an incision of about 2 to 4 mm. No flap is made.
- PRK and LASEK: The surface skin of the cornea is removed or moved aside, the excimer laser reshapes the surface, and a bandage contact lens protects it while the skin regrows over 3 to 5 days.
- ICL: A flexible collamer lens is inserted through a small incision and sits behind the iris, in front of your natural lens. No corneal tissue is removed.
Who LASIK suits and does not suit
LASIK suits people with low to moderate short sight, long sight or astigmatism, corneas of adequate thickness and normal shape, and no significant dry eye. Typical treatable ranges are up to around minus 8 to minus 10 for short sight and lower limits for long sight, depending on the cornea. Its main appeal is speed: most people see well the next day with mild discomfort for a few hours.
It does not suit thin or irregular corneas, because removing tissue under a flap weakens the cornea and can, rarely, lead to ectasia, a progressive bulging. It is often avoided in contact sports, martial arts and some military or police roles because a flap can be dislodged by a direct blow, even years later. It can also worsen dry eye for several months.
Who SMILE suits and does not suit
SMILE suits short sight with or without astigmatism, broadly from about minus 1 to minus 10. Because the incision is small, fewer corneal nerves are cut, and many surgeons consider it somewhat kinder on dry eye than LASIK in the early months. There is no flap to displace, which appeals to active people.
It is less versatile. Availability for long sight is limited, very low prescriptions are harder to treat, and visual recovery is often a little slower than LASIK, with sharpness building over several days to weeks. Enhancements, if needed later, are usually done as PRK rather than by repeating SMILE.
Who PRK suits and does not suit
PRK suits thinner corneas where a flap would leave too little tissue, people in contact sports or jobs with a risk of eye injury, and some corneas with surface irregularities. Long-term visual results are comparable to LASIK.
The cost is the recovery. Expect 3 to 5 days of significant discomfort, light sensitivity and watering, and blurred vision that improves gradually over 2 to 6 weeks, sometimes longer before it is fully crisp. There is a small risk of corneal haze, which is why surgeons often use mitomycin during surgery and ask you to wear sunglasses outdoors for months. It does not suit a very short trip or someone who must drive or work within days.
Who ICL suits and does not suit
ICL suits high short sight, often from around minus 6 up to about minus 18, thin corneas, and significant dry eye, where lasers are unsuitable. Visual quality in high prescriptions is often very good because the cornea keeps its natural shape. The lens can be removed or exchanged if needed.
It requires enough space in the front chamber of the eye, which is measured beforehand, and it is usually offered between about 21 and 45 years of age. It is intraocular surgery, so the rare but serious risks include infection inside the eye, raised eye pressure and early cataract. Eyes are commonly treated on separate days. It does not suit people with a shallow anterior chamber, glaucoma or a low endothelial cell count.
Recovery and travel timing compared
Plan your trip around the slowest part of your recovery and the first follow-up checks, not around the procedure itself. These are typical figures and your surgeon's schedule takes priority.
- LASIK: Check at day 1. Most people can fly after 1 to 3 days. Stay about 3 to 4 days in total. Avoid eye rubbing, swimming and eye make-up for around 2 weeks.
- SMILE: Similar to LASIK. Check at day 1, stay about 3 to 4 days. Vision sharpens over several days.
- PRK: Bandage lens removed at about day 4 to 5. Plan 6 to 7 days. Expect to function poorly for the first few days and arrange help.
- ICL: Pressure check within hours and at day 1, second eye often 1 to 7 days later. Plan about 5 to 8 days.
What screening should include, and the limits of a short trip
A proper assessment includes corneal topography and tomography, thickness measurement, pupil size in dim light, tear film tests, a dilated retinal examination and a stability check of your prescription. Soft contact lenses should be left out for about 1 to 2 weeks beforehand, and rigid lenses for longer, because they temporarily change the shape of the cornea.
The drawback of travelling is that screening and surgery often happen on consecutive days, which leaves little room to reflect if the advice changes. Decide in advance that you will accept a no. Arrange an optometrist or ophthalmologist at home for checks at around 1 month and 3 months, and bring your surgical report and scan printouts.
When to get medical help
Seek urgent eye care if you have increasing pain, a sudden drop in vision, marked redness, discharge, or growing light sensitivity after the first day or two. After ICL, severe eye pain with headache, nausea and halos can mean a pressure spike and needs same-day treatment. After LASIK, a blow or hard rub to the eye followed by blur or pain may mean a displaced flap. Flashes, a shower of floaters or a curtain in your vision need urgent retinal assessment, whatever procedure you had.
This guide is general information and does not replace advice from the doctor treating you. If you would like a specialist to look at your own case, send your reports and photographs: a Clinic-Y coordinator replies within 24 hours, and the case review is free.
Frequently Asked Questions
Will I ever need glasses again?
Possibly. Most people reach good unaided distance vision, but a small percentage need an enhancement or thin glasses for night driving. From your mid 40s, reading glasses are normal because the natural lens stiffens with age, which none of these procedures treats.
Are night halos and glare permanent?
They are common in the first weeks to months and usually fade as the eye heals. A small number of people keep some night symptoms, more so with large pupils or high prescriptions. Ask how your pupil size compares with the planned treatment zone.
Can I have laser surgery if I am pregnant or breastfeeding?
It is usually postponed. Hormonal changes can shift your prescription and dry the eyes, and some of the eye drops are avoided. Most surgeons advise waiting a few months after you finish breastfeeding and rechecking stability.
What if I am over 50?
At that age the natural lens is starting to change, and cataract may be on the horizon. A lens replacement procedure is sometimes discussed instead, but it has its own risks. A frank conversation about how long a corneal laser result would serve you is worthwhile.