Amblyopia generally refers to an eye condition that causes poor visual perception. Also known as "lazy eye," amblyopia means the vision in one eye is reduced, and the brain and the eye are not working together to focus on objects. It is often correctable if treated in early childhood. Treatment can involve working or training the "lazy" eye, often by covering up the good eye with a patch until the affected eye is strengthened. Amblyopia can be characterized by a squint or eyes that turn inward or outward. It can also be caused by not using one eye, for example, in the case of congenital cataract or partial absence of the iris.