What are the odds of suceeding an eye operation? (to stabilize your vision)

Depends. The odds depend on what surgery is needed and on various clinical characteristics of your particular eye. Fortunately for eye surgery, success rates are incredibly high and risk of complications are very low.
Depends on procedure. Surgery to correct vision is called refractive surgery and is most commonly associated with laser procedures such as lasik and prk. With modern laser technology complications are rare and long term success is high. You should discuss the technique and technology with your surgeon. You should also ask about their personal success rate for each procedure that is being offered.