Dd who was 5 in August has had glasses since Easter, basically because she is long sighted, and her right eye had reduced vision - fairly dramatically lower than the left. For the last 8 weeks we've been patching for an hour a day.
Today, her right eye was massively improved, she could see the same card as with her left, just 2 letters she couldn't do. So 8 weeks more of patching, then recheck the vision, then 6 months or so of just glasses to make sure the vision doesn't drop again, then she should only need her glasses for school work.
It is amazing what 8 weeks patching will do!