Laser vision correction does not prevent cataract, and it does not cause it. Cataract is a clouding of the eye's natural lens that comes with age for most people, and it arrives on its own schedule whether or not the cornea was reshaped decades earlier. What laser correction does change is one specific step of the cataract operation: the calculation that chooses the power of the artificial lens. That step is where records from your original procedure become useful, and it is worth knowing this now, while those records are easy to get.
Two different parts of the eye
Vision correction by laser works on the cornea, the clear window at the front of the eye. Cataract surgery works on the lens behind the pupil, replacing it with an artificial one. The two are separate structures, and treating one does not use up or damage the other. This is why a patient who had SMILE or LASIK in their twenties or thirties can have cataract surgery later without any conflict between the procedures.
Where the complication actually is
An artificial lens has to be chosen in a specific power for your eye, and that power is calculated from measurements: the length of the eye and the curvature of the cornea. The standard formulas for this calculation assume a cornea with a natural shape. After laser correction the front surface of the cornea has been flattened or reshaped in a way the standard measurement can misread, because the relationship between the front and back surfaces is no longer the one the formula expects.
The result is not that cataract surgery becomes unsafe. It is that the lens power calculation becomes harder to get exactly right, and a lens that is slightly off in power leaves a residual prescription that would otherwise have been avoided. Surgeons have methods for this: formulas developed specifically for post-laser eyes, measurements that capture the back surface directly, and calculations that use data from before and after the original procedure. The last of those is the one that depends on you.
What to keep, and why
The most useful pieces of information are the corneal curvature readings taken before your laser procedure, your prescription before and after it, the date, and the procedure and platform used. With those, a surgeon years from now can see how much your cornea was changed and correct the calculation accordingly. Without them, the surgeon is working from the reshaped cornea alone, using methods that are good but less precise.
Ask the clinic for a copy of your pre-operative measurements and your surgical summary before you fly home. Keep it with documents you do not throw away. A photograph of the pages stored in more than one place is enough. The point is that the cataract surgeon you see in twenty or thirty years, very possibly in another country, will have something to work from.
Where an ICL sits in this
An implantable collamer lens does not reshape the cornea. When cataract eventually develops in an eye with an ICL, the ICL is removed at the time of the cataract operation and the natural lens is replaced as usual. Because the cornea is untouched, the lens power calculation uses the standard measurements. This is one of several differences between the two routes, and it is not usually the deciding one, but it is worth knowing.
What this means for overseas patients
Having your vision correction in one country and your cataract surgery decades later in another is entirely workable. What makes it workable is the record. It is far easier to obtain on the day you leave than to request from abroad many years later, and it is one of the few things from your trip that will still be doing a job long after the recovery is forgotten.
GS Eye Center (GS안과) is an eye clinic at Gangnam Station Exit 1, Seoul, open since 2005. Overseas patients can request a copy of their pre-operative measurements and procedure summary before they leave, and it is the document from the trip most worth keeping for decades.