Amblyopia (or lazy eye) is the most common cause of poor vision in children. Amblyopia occurs because the part of the brain that deals with vision for that eye has failed to develop normally.
The vision centre in the brain is constantly developing during the first seven to eight years of a child’s life. If the vision is interfered with in any way then the brain will start to prefer one eye over the other and the vision in the other eye will suffer. To reverse the process and correct the vision in the poor eye, it is necessary to make the brain use this eye again.