Could you explain what is optical nerve hypoplasia?

It is: A congenital condition in which the optic nerve, the nerve between the eye and brain, does not develop properly. Vision can be normal or totally blind or anything in between. This can be associated with other congenital disorders and this possibility should be explored in the child.

Birth defect: This is a condition at birth in which the optic nerve to one or both eyes is under-developed and the vision is impaired in that eye. It usually causes permanent loss of vision and occasionally is associated with other defects of the nervous system.