If you were going to "buy a refractive surgery," you'd want to know some hard numbers about outcomes. You wouldn't want to risk your vision unless you had a very good chance of success. Unfortunately, most of the victims of LASIK and other refractive surgeries were sold their procedures based on visual acuity scores. Probably 99% of the public believes that good vision means 20/20. What most patients didn't know---and were never told---is that 20/20 is only part of the story. Those who market LASIK know this, and capitalize on the percentage of patients who reach 20/20. But in fact, 20/20 is a complete nightmare for many refractive surgery patients. Consider the bottom four charts below. Except for the bottom right chart, all are 20/20. Many patients have this vision or worse, and have been told by their surgeons that their surgery is a success. If you don't believe it, go to TheLASIKFlap forum and find out the truth.
The 20/20 line is just above the red line on the charts below. In all but the last example, the 20/20 line can be read. If you have refractive surgery and have an outcome similar to these, your surgeon may deny that anything is wrong with your vision because you are 20/20. If you sue, the jury will be told that you are 20/20, and because the jury probably believes that eyechart scores are all there is to vision, you will probably find yourself unable to recover any compensation for your losses. In fact, you may not even be able to find an attorney to take your case.
Some images courtesy VisionSimulations.com