@Eva,
Well, Eva, how do you know, until you do many surgeries? My miserable left eye is a result of what is clear to me now as a complete sliperoo in miniseconds. Years of my life ever after would have been different. I'm not too charmed with that surgeon now.
I take it there is an element of practice going on all the time.
Sloppiness, that is another question, and hard to prove.