Explanation

Amblyopia, also called lazy eye, means that you can't see properly with one of your eyes. It is caused by lack of use of the eye when you are very young. You get it when your eyesight is still developing, and although it usually only affects one eye, very rarely it can affect both.

You can see when you are born, but as you grow, the pathways between your eyes and your brain keep developing. Your brain learns how to understand what your eyes see. This process goes on until you are about 7 or 8 years old. After that age, these pathways have finished developing and can't change. You get amblyopia if your vision is reduced and doesn't develop properly.