What is strabismus?
Strabismus is having one eye that looks in a different direction than the other eye. The eye may look outward (called walleye) or inward (called cross-eyes).
Strabismus can start in the first months of life or begin at any time in childhood
Strabismus is usually caused by blurry vision in one eye or by an uneven pull in eye muscles
Your child may have double vision Vision, Double Double vision is seeing two images of one object. Double vision may occur when only one eye is open (monocular diplopia) or, more commonly, when both eyes are open (binocular diplopia). Binocular... read more or a sore neck from twisting the head to see better
Strabismus sometimes gets better on its own, but most children need special eyeglasses, contact lenses, or surgery
Without treatment, severe strabismus can cause permanent vision loss
What causes strabismus?
Strabismus is caused by:
Blurry vision (farsightedness)
Uneven pull of the muscles that control the position of the eyes, causing them to point in different directions
Paralysis or weakness of a nerve that controls eye movement
A birth defect of the eyes
Rarely strabismus is caused by a type of eye cancer that happens mostly to young children (retinoblastoma Retinoblastoma Retinoblastoma is a cancer of the retina, the light-sensing area at the back of the eye. Retinoblastomas can result from a genetic mutation. The child may have a white pupil or cross-eyes or... read more 
) or an eye injury.
Children are at higher risk of strabismus if they:
Were born too early (premature)
Have people in their family with strabismus
Have certain inherited disorders such as Down syndrome
Their mother used illicit drugs or alcohol while she was pregnant
What are the symptoms of strabismus?
You may notice:
Your child squints a lot or covers one eye
Your child's eyes look like they don't point the same way
Your child complains of eye strain, neck strain, or double vision
Because visual signals from the two eyes don't match, your child's brain starts to ignore signals from the affected eye. This causes a form of vision loss called amblyopia Amblyopia Amblyopia (also called lazy eye) is a particular kind of vision loss in children. If the images sent to the brain by each eye don't match, then the brain ignores what one of the eyes sees. Amblyopia... read more . If your child's strabismus isn't corrected before about 8 years old, the vision loss may be permanent.
How can doctors tell if my child has strabismus?
Children should get regular eye exams to check for vision problems and strabismus, starting at a few months of age. Doctors will check your child's eyesight and see if both eyes look and move in the same direction.
If strabismus is caused by a weak or paralyzed nerve, doctors may do a CT (computed tomography) scan Computed Tomography A CT scan uses a large machine shaped like a large donut to take x-rays from many angles. A computer then takes the x-rays and creates many detailed pictures of the inside of your body. Each... read more 
or MRI Magnetic Resonance Imaging (MRI) MRI is a test that uses a machine with a powerful magnet to make pictures of the inside of your body. A computer records changes in the magnetic field around your body. The computer then uses... read more 
(magnetic resonance imaging) of the brain or spine.
How do doctors treat strabismus?
If your child has strabismus, an eye doctor (ophthalmologist) can decide what treatment might be needed. Strabismus that's mild or comes and goes may not need to be treated. Treatment aims to align the eyes so they're looking in the same direction and see equally well. Depending on the cause and symptoms of your child's strabismus, doctors may:
Prescribe eyeglasses or contact lenses
Have the child do eye exercises
Sometimes, do surgery to loosen or tighten the eye muscles so the eyes can align
It's important to treat strabismus as it can cause amblyopia Amblyopia Amblyopia (also called lazy eye) is a particular kind of vision loss in children. If the images sent to the brain by each eye don't match, then the brain ignores what one of the eyes sees. Amblyopia... read more (lazy eye).
