Strabismus and Amblyopia Symptoms & Causes

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What causes strabismus?

Experts don’t completely understand the cause of strabismus, but it results from the failure of the eye muscles to work together.

Idiopathic (resulting from an unknown cause) strabismus is the most common type. Other conditions can also cause strabismus:

Risk factors for strabismus include the following:

  • Family history of strabismus
  • Prematurity or low birth weight
  • Retinopathy of prematurity
  • Conditions that affect vision, such as cataracts, severe ptosis and corneal scars
  • Muscular abnormalities
  • Neurological abnormalities
  • Amblyopia (or lazy eye) 

How common is strabismus?

As many as 4 percent of children have strabismus.


What are the symptoms of strabismus?
Babies and children with strabismus should be checked right away to prevent amblyopia, which results in loss of vision and depth perception due to the misaligned eye. Amblyopia can occur even if the eye is only slightly misaligned, because a developing child's brain will stop communicating with that eye, shutting it off. This is why amblyopia is sometimes referred to as "lazy eye". 

Unfortunately, it isn't always easy for parents to tell if a child's eyes are misaligned, particularly in those children with a mild case of strabismus. If your child is showing any of the following signs and symptoms of strabismus, you should call today and schedule an appointment for an eye exam with one of our pediatric ophthalmologists.

  • Strabismus in newborns. Many parents are told that a baby’s eyes may not be completely aligned in the first three months of life. It is not unusual for a baby's eyes to occasionally wander outward, but if this happens all the time or if the eyes cross inward, especially constantly, your baby should have an eye exam.
  • Strabismus after 3 months of age. If you notice one or both of your baby's eyes wandering out or crossing in after 3 months of age, your baby should have an eye exam.
  • Head tilting or squinting. Children with strabismus may tilt their head in order to effectively line up the eyes to use them together or they may squint one eye, especially in bright sunlight, to block out a double image resulting from the misaligned eyes pointing in different directions. Children who show these signs should have an eye exam.
  • Red eye reflection in one eye. An annoyance in family pictures, the "red eye" reflection can sometimes provide valuable information about vision. If "red eye" is showing in only one eye rather than both eyes, it may be a tip-off that your child is having a vision problem and should have an eye exam.
  • When a sibling has strabismus. If a brother or sister has been diagnosed with strabismus, it is a good idea to have your baby or child examined, even if there are no obvious signs of the problem.


What are the complications of strabismus?

  • Amblyopia (lazy eye) occurs in up to one-half of younger children.
  • Diplopia (double vision) can occur in acquired strabismus in older children and adults.
  • Problems in socializing or working resulting from the appearance and function of the eyes

What is the long-term outlook for my child?

It depends upon the underlying cause of your child’s strabismus, but what is true in all cases is that the sooner the condition is diagnosed, the more effective the treatment will be.

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- Sandra L. Fenwick, President and CEO

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