Amblyopia in 4 year old

Hi All,

My 4 year old has been diagnosed with amblyopia. He is prescribed lenses with +2 on left eye and +1 on right eye. The Dr says that glasses are something he will have to always wear. My questions with anyone with the same condition:
1) Is this curable?
2) do you have any recommendations for exercises that will help improve his condition?

My concern is that he is only 4 and with time it might only get worse.

Thanks in advance!