Can lazy eye be completely cured? I've heard that lazy eye can't be cured, only improved. Is that true? My 2-year-old son was just diagnosed with it, and his doctor said that as long as he wears his patch and glasses, he should be cured within a few month

Turning off vision. As a child grows, their eyes may have different strength, or weakness in an eye muscle may allow one to line up wrong. The fuzzy or double vision confuses the brain. Over time the brain may begin turning off the input of one eye & keep the best.If caught in time,the patching or glasses help retain the vision in the weaker eye & push it improve & stay on.Otherwise the brain can turn it off.
"Lazy . "lazy eye" tends to mean different things to different people. If you mean amblyopia (which is what it sounds like), it means that the brain begins favoring one eye over the other (or possibly even rejecting both eyes) and the wiring between the eye and the brain doesn't form properly. If the cause is addressed early in life like prescribing glasses, doing eye muscle surgery or removing cataracts, there is a greater chance of vision returning. Patching the good eye forces the child to look out of the "bad eye" so it helps lays down that wiring. Once the child is 8 or so, there is much less flexibility and the damage is already done.
It . It depends on the age and the severity at which it is diagnosed. Earlier (before age 5) and mild amblyopia (lazy eye) can be fully cured with proper treatment.