Well, generally speaking, from your description, I have to say your child may suffer from crossing eyes, which is also named as strabismus. Strabismus refers to the condition in which eyes don't look at the same point at the same time. And according to some experts, some exercises can just correct it. So you can just have a try. First, you can place one of your index fingers on the tip of your nose. And then, keep both eyes focused on your fingertip, slowly moving your finger away from your nose until your arm is completely straight. Finally, what you should do is to slowly return your finger to your nose, staying focused on your fingertip the whole time. And then, just repeat it.