Hi and sorry to hear about your child's
hypermetropia. I understand your worries and I know they are real.
Lenses often resolve eye sight abnormalities instantly. However, he must continue to wear glasses if he wishes to maintain the good sight. I am sure the other eye is covered just to make sure that the child is able to see well with the affected eye after correction. This is so in order to avoid the normal eye interfering and making interpretation of results difficult.
When the doctors will conclude the evaluation period, the right eye would be opened but your son will continue to put on glasses to have a good vision.
Getting cured is rarely the outcome. Correction of sight is the main goal of treatment now. However, there are now
eye surgery techniques(LASIK) that you may want to consider if you are not satisfied with your child putting on lenses. Please, discuss this with your treating physician.
I do hope I have been able to provide the answers to your question. If there is more you desire, please feel free to contact me.
Wish your son a speedy recovery.