All the children should have a careful eye exam at the age of 3, which is the best way to detect whether they have amblyopia. If they have got amblyopia, they can be treated as early as possible. If you pass your teens, you may find difficult achieving good results.
It is said that children should have a complete eye exam when they are 3 years old so that it can determine whether they are suffering amblyopia. Generally speaking, if parents notice that their children reading their books too closely, or without one eye focusing while looking at something, they should take their children to hospital to have a regular eye exam so that they can detect amblyopia as early as possible.