Why do some kids have tape over one of their eye glasses lens?

Amblyopia: When one eye stops working right, the doctor will often cover the good eye to force the bad eye to start working again. The cause of this is because the 2 eyes don't work together & it is easier to see with one eye than 2 that make you see double. Vision therapy with a developmental optometrist can often fix the problem.

Amblyopia/Strabismus: I agree with dr. Block that some kids have one "lazy" eye that needs to be made to work by occluding the "good" eye with tape, a patch, or drops. Vision therapy (VT) may or may not work to improve visual function, but prolonged attempts at VT may delay needed surgery if the eyes become misaligned. Any such patient needs to be seen by a pediatric ophthalmologist before therapy decisions are made.