Strabismus is when an eye either “turns in” or “turns out”

It is a vision condition in which a person cannot align both eyes simultaneously. One or both of the eyes may turn in “cross eyed” (esotropia), out “wall eyed” (exotropia), up (hypertropia) or down (hypotropia).

Someone suffering from strabismus will use one eye to look at something while the other is pointing in a different direction. Strabismus results in double vision and poor depth perception and can get worse with time if left untreated.


An eye turn may be constant (when the eye turns all of the time) or intermittent (turning only some of the time, such as concentrating at a near task, day dreaming or when under stressful situations).

Most strabismus develops in infancy or early childhood. Strabismus often develop in children when there is confusion in the visual space. It is rare that a child is born with it. Adults after a traumatic brain injury or stroke can also develop strabismus.

In many cases, the problem begins when the brain learns to ignore the misaligned eye, processing only what the other eye sees. In such a case, the vision from the misaligned eye is suppressed, leaving only one eye to function properly. This is a condition that rarely corrects itself, and if not treated early, usually leads to the loss of binocular vision and depth perception.

When the images from the misaligned eye are continuously suppressed, the vision in that eye fails to develop hence the term “lazy eye”. This leads to a condition known as amblyopia in which the vision in the misaligned eye is reduced. Recent scientific research has disproven the long held belief that children with amblyopia can’t be helped after age 7. Sue Barry, a neuro scientist, learned to use her eyes together and started seeing 3D at 48 years of age.

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