by
Mamisoa Andriantafika
LASIK is more than thirty years old. Millions of people have been treated worldwide, and the earliest patients now have several decades of hindsight. One question comes up again and again in consultation: “Doctor, does it last a lifetime?”
The short answer is reassuring: the correction delivered by the laser is durable. The full answer requires one simple distinction. The laser corrected the cornea, and that correction stays stable. The eye itself keeps ageing normally. This article reviews what becomes of treated eyes, ten or twenty years after refractive surgery.
We now have studies with genuine hindsight. A Spanish team followed patients for ten years after LASIK for myopia of up to -10 dioptres. Its conclusion is clear: the technique is safe and effective, with a slight myopic regression that slows down over time. Another follow-up published at twelve years confirms that stability, including for moderate to high myopia.
A large review of the literature pooled the results of nearly 68,000 eyes treated with modern lasers. It reports that 99.5% of eyes see at least 5/10 without any correction after surgery, and that fewer than 1% of eyes lose two lines of best corrected acuity. These figures place LASIK among the best documented procedures in medicine.
The cornea reshaped by the laser does not “grow back”. The correction stays stable for decades.
The reason for that stability is anatomical. The laser sculpts the corneal stroma, a tissue that does not regenerate. The shape given to the cornea is therefore permanent. The small variations observed over the years almost never come from the cornea itself. They come from the rest of the eye.
LASIK corrects the cornea, but it does not stop the eye from ageing.
A slight regression can occur in patients treated for high myopia. It appears mostly in the first few years, then it slows down. It usually stays modest and does not bring the patient back to the original correction. This phenomenon does not mark a “failure” of the laser: it is part of the natural history of very myopic eyes.
The rest of the evolution does not concern the cornea. The crystalline lens, the natural lens sitting behind the pupil, changes with age in everyone. It loses its flexibility around 45, then it can become cloudy after 60. The table below sums up what stays stable and what evolves.
| Structure of the eye | Effect of LASIK | Evolution with age |
|---|---|---|
| Reshaped cornea | Correction of the refractive error | Stable for decades |
| High initial myopia | Corrected by the laser | Slight regression possible, slowing down over time |
| Crystalline lens after 45 | None: the laser does not act on the lens | Loss of flexibility: presbyopia appears |
| Crystalline lens after 60 | None: the laser does not act on the lens | Clouding possible: this is cataract |
Around the age of 45, reading up close becomes harder. This phenomenon is called presbyopia. It affects everyone, treated or not. The crystalline lens gradually loses its ability to focus at near, and LASIK changes nothing about that since it acts on the cornea.
Some patients treated twenty years earlier are surprised by it: “My laser has stopped working, I have to wear reading glasses!” In reality, their distance correction is still in place. Their eye has simply become presbyopic, like that of everyone in their forties.
Treated or not, everyone becomes presbyopic after 45. LASIK neither causes presbyopia nor prevents it.
Solutions exist at that stage. Reading glasses remain the simplest answer. A new laser treatment adapted to presbyopia can be discussed, as can pilocarpine-based eye drops. The choice depends on age, on the remaining correction and on each person's expectations. A consultation allows all of this to be discussed calmly.
Cataract surgery works very well on an eye already treated with the laser. The key is a suitable implant calculation.
After 60 or 70, the crystalline lens can become cloudy. This is cataract, a natural evolution that also concerns eyes treated with LASIK. The good news is simple: cataract surgery proceeds normally on an eye already treated with the laser.
One point does deserve attention, however. During that surgery, the surgeon replaces the crystalline lens with an implant whose power is calculated from the shape of the cornea. Classic formulas assume a natural cornea. On a cornea reshaped by the laser, they must be adapted, otherwise the calculation will be wrong.
Two habits make that future surgery easier. Keep your pre-LASIK data, because it helps with the implant calculation. Also bear in mind that modern tomographers such as the Anterion measure both corneal surfaces directly. They allow a reliable calculation even without the older measurements.
What if a small amount of myopia reappears years later? A laser enhancement can be discussed. It remains rare, because the vast majority of patients keep satisfactory vision without any further procedure.
Before any enhancement, the surgeon checks three things. The correction must have stabilised. The remaining corneal thickness must be sufficient for a new treatment to be performed safely. The ocular surface must be healthy, because a poor quality tear film distorts the measurements. If those conditions are met, the enhancement is carried out with the same precision as the initial procedure, on latest generation laser equipment.
Enhancement is possible, but it stays rare: most patients will never need one.
In some cases, the surgeon prefers a surface PRK rather than lifting the flap again. That technical choice depends on how long ago the surgery was performed and on the state of the cornea. It is decided case by case, after a complete work-up.
Twenty years after LASIK, the picture is clear. The correction delivered by the laser holds over time, and studies at ten years and beyond confirm it. The eye, for its part, continues its natural evolution: presbyopia arrives after 45, and cataract can occur much later. These stages do not call the surgery into question, and each of them has its own solution. A regular eye examination remains useful to accompany the ageing eye, not to monitor the laser correction.
