You also cut the article to fit your point. E.g. full text regarding 574 participants: =================================== quote But many of the trial’s 574 p

You also cut the article to fit your point. E.g. full text regarding 574 participants: =================================== quote But many of the trial’s 574 participants reported having visual aberrations and dry eyes before surgery, and the study concluded that Lasik slightly reduced the prevalence of these problems. Three months after surgery, however, glare, halos and double vision were common, affecting 50 to 60 percent of all patients, with up to 5 percent characterizing them as “very” or “extremely” bothersome. Even after six months, some 41 percent of patients reported visual aberrations, with nearly 2 percent — or one in 50 — saying the symptoms presented “a lot of difficulty” or “so much difficulty that I can no longer do some of my usual activities.” And one-quarter of the patients followed six months had mild to severe dry eyes. =================================== end quote Note that wording here is unclear, because "many" is not quantified and we don't have percentage change over time here. Did it increase or not and by how much. But due to this it is possible to interpret this part however your want - that lasik made things worse or that it didn't.