A strabismus, commonly referred to as a squint, is when the two eyes are not straight resulting in a misalignment of the visual axes. An inward turn is called an esotropia and an outward turn is an exotropia. Strabismus can present as an adult but is more commonly noted in children. In most of these cases, the cause is unknown and where it is present from birth, it is known as a congenital strabismus. With strabismus, because the eyes are misaligned the brain can be confused by the two different images that it receives from each eye. In children, the brain may learn to ignore the image from the weaker eye (suppression) and if left untreated, this could lead to a lazy (amblyopic) eye. Sometimes, the lazy eye can cause the strabismus. A strabismus can also present itself after traumatic brain injury, certain toxins, systemic disease or after vision loss from ocular disease or injury.