Children ages 3 to < 8 years with severe/dense amblyopia (visual acuity of 20/100 to 20/400 in the amblyopic eye) will be enrolled and randomized into two groups: 1) standard 6-hour patching group or 2) 12-hour IO-therapy glasses group.~Children ages 3 to < 8 years with deprivation amblyopia associated with congenital or developmental cataracts (visual acuity of 20/40 to 20/400 in the amblyopic eye) will be enrolled.~Children ages 3 to < 8 years with myopic anisometropic amblyopia will be enrolled into an intermittent occlusion therapy glasses (AmblyzTM) group.~According to visual acuity, they will receive one of two IO-therapy glasses treatment regimens: 1) If the amblyopic eye is between 20/40 to 20/80 inclusive, 4-hour IO-therapy glasses or 2) If the amblyopic eye is between 20/100 to 20/400 inclusive, the child will receive12-hour IO-therapy glasses.
This study is designed to evaluate the effectiveness of a novel amblyopia treatment - Intermittent occlusion therapy (IO-therapy) glasses (AmblyzTM) in treating severe amblyopia.~Children ages 3 to 8 years with severe amblyopia (visual acuity of 20/100 to 20/400 in the amblyopic eye) will be enrolled and randomized into two groups: 1) standard 6-hour patching group or 2) 12-hour IO-therapy glasses group.~The study also observe the effectiveness of IO-therapy glasses on two types of difficult amblyopia: deprivation amblyopia associated with congenital or developmental cataract, and myopic anisometropic amblyopia.