Crossed Eyes (Strabismus) What Is It? Crossed eyes, also called
strabismus, occurs when the eyes appear to be misaligned and
point in different directions. Strabismus can occur at any age,
but is most common in infants and young children. It can be seen
in up to 5% of children, affecting boys and girls equally.
Strabismus can occur part of the time (intermittent) or all of
the time (constant). Intermittent strabismus may worsen when the
eye muscles are tired -- late in the day, for example, or during
an illness. Parents may notice their infant's eyes wandering
from time to time during the first few months of life,
especially when the infant is tired. This occurs because the
infant is still learning to focus his or her eyes and to move
them together. Most babies outgrow this intermittent strabismus
by the age of 3 months. Strabismus can be caused by problems
with the eye muscles, with the nerves that control the eye
muscles or with the brain, where the signals for vision are
processed. Strabismus can accompany