Lasik waiver for pupils larger than normal

I was wondering that when you have your pre op exam is there a form that you would have to sign if the doctor tells you your pupils are larger than normal but you still want to have lasik after being warned? Is the doctor obligated to tell you this information prior to surgery? I dont think most high end surgeons would risk a career by doing lasik on someone who is not a candidate. I've never signed such a form but read where people had it done even after being warned and had horrible outcomes.