What is the quickest in most affective way to fix a lazy eye if you are born with it and are trying to fix it at the age of 15?

See a pediatric...: If by lazy eye you mean that the eyes are not aligned then this is a very common problem that can and should be fixed by an experienced pediatric ophthalmologist. In most cases surgery will be required. Ask for a referral from your pediatrician. The results are usually quite good depending on the cause. If you mean an eye with poor vision, this is a different problem & harder at address at 15.

Depends on how lazy : Your eye is. As early as a decade ago eye mds were sure lazy eye is treatable only till age 9. But recent research has shown mild to moderate amblyopias specially if due to astigmatism are treatable till late teens. If you have a high farsightedness or high astigmatism (meridional amblyopia) lasik or prk and half day patching of good eye may have surprizingly good results. See an eye md.