Please explain if it is true that a lazy eye leads to irreversible vision loss?

Turning off vision. The human brain utilized the input of both eyes to aid in depth perception/distance etc. As you grow, the 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 turn off the input of one eye ; keep the best. That process is called amblyopia. If not caught and treated in time it is permanent.