They are. Lasik is a refractive surgery to correct myopia, hyperopia and astigmatism. In some rare cases, people develop post lasik ectasia (corneal thinning and loss of visual acuity) and in even more extreme cases, this requires a cornea transplant. A cornea transplant is as the name suggests, where you remove your cornea (fully or partially) and replace it with a donor cornea.
What I'm talking about here is a worst case scenario which happened to a lasik patient. Lasik -> Post Lasik-Ectasia -> Corneal Transplant -> High Eye Pressure -> Blind.
This is the story which I found:
$1 under "Lasik in 2006, then Ectasia a year later, then Pressure Spike".