Esotropia, often referred to as “crossed eyes,” is diagnosed when one or both eyes turn in. This is not typically a painful condition, though vision may be blurry in one or both eyes.
A diagnosis of exotropia means that one eye looks straight ahead and the other turns out, toward the temple. Just as with esotropia, vision may be blurred. Typically there is not pain.
A vertical deviation is diagnosed when one eye shifts up or down while the other stays in a forward position. Since the eyes do not line up, vision will likely be blurred, though pain should not be present with vertical deviations.
Amblyopia, also known as “lazy eye,” is decreased vision in one or both eyes due to abnormal development of vision in infancy or childhood. In amblyopia, there may not be an obvious problem of the eye. Vision loss occurs because nerve pathways between the brain and the eye aren’t properly stimulated. The brain “learns” to see only blurry images with the amblyopic eye even when glasses are used. As a result, the brain favors one eye, usually due to poor vision in the other eye. It is the leading cause of vision loss in children.
Nystagmus is an involuntary shaking or “back and forth” movement of the eye. There are two types of nystagmus – congenital and acquired. Congenital nystagmus typically presents itself in children between 6 weeks and 3 months of age. There is no known cause. Acquired nystagmus occurs later in a child’s life and can be associated with myriad medical conditions, including cataracts, strabismus and amblyopia.