It just re-shapes your lens via subtraction. you can have it done as many times as your lens has enough material to be molded into the required geometry via removing material.
Naively searching seems to mostly get well SEO'd results from LASIK related companies making claims like "In general, there is no limit on how many LASIK procedures you can get in your lifetime"[0]. Though that is followed by "The thickness of the cornea is one of the main determinations regarding the safety of multiple LASIK surgeries" in the same article which seems to contradict the previous statement as there is clearly a limit before it becomes unsafe to perform another procedure.
Meanwhile on a very short search, I cannot seem to find any study or report about literally anyone having more than two laser eye surgeries.
I did find an FDA guideline from 2022 that lists a surprising number of risks for laser eye surgeries[1].
I am ineligible for the procedure as my farsightedness is too severe when coupled with a thin portion of my cornea
I would guess the first surgery is generally the most severe and the followups require less material removal, but I think your research is probably more detailed than mine at this point.
