Vision Center is funded by our readers. We may earn commissions if you purchase something via one of our links.
In this article
Strabismus, also known as tropia or crossed eyes, is a condition that causes eye misalignment. The eyes point in different directions and do not line up.4
In some cases of crossed eyes, one eye looks straight out while the other eye turns in or out, up or down. In other cases, both eyes turn in or out, up or down.
With normal vision, both eyes look in the same direction. The brain combines the views from both eyes into a single image with depth perception.
All six eye muscles must move together to focus on an image.1, 6 With strabismus, they don’t. But the brain needs both eyes to see correctly. Therefore, strabismus takes a toll on vision.
There are four main types of strabismus:2
The two most common forms of strabismus are:2
For most children with strabismus, the cause is unknown. More than half of strabismus cases in children are present at or right after birth. This is known as congenital strabismus.
Some people with strabismus may not experience any symptoms. Others experience all or some of the following:2
Here are a few causes of strabismus in adults:1, 6
Some other disorders are also associated with crossed eyes in children. These include:5, 6
If strabismus is left untreated, it can cause more severe vision problems.
For example, strabismus can cause a lazy eye (amblyopia). A lazy eye has weaker muscles. The brain uses the stronger eye more, worsening the weaker eye over time.
Strabismus can also cause health issues related to poor vision. This includes headaches or injury from difficulty seeing.
Visit a doctor if you are having trouble seeing clearly. You should also see a doctor if the worsening vision issues are not improving with treatment.
If you are worried about your child’s eyesight, reach out to your doctor right away. If your child is at least 3 months old, and their eyes are misaligned, schedule an eye exam. Even if their eyes only appear misaligned at times, get them checked.4
Most children who develop strabismus are diagnosed between the ages of 1 and 4 years old. Some children develop strabismus after age 6 due to other health conditions.3
Your doctor will perform an eye exam to diagnose you or your child with strabismus. During an eye exam, the doctor will assess visual acuity. This includes depth perception and how well you can see letters or numbers at different distances.
They will also perform a retinal exam and a neurological exam.4
Treatment for strabismus varies depending on the cause, the price, and your candidacy, among other factors.
Here are some treatment options that your doctor may recommend:
The outlook for strabismus is positive if it is treated early. Treatment can improve symptoms like double vision, difficulty understanding depth perception, and vision loss.
If strabismus is left untreated, it can lead to more vision issues down the line.2
Strabismus can cause amblyopia when the brain starts to ignore the affected eye and favors the healthy eye. Amblyopia can also cause strabismus.6
Crossed eyes are a common eye problem that can affect vision. If you or someone you know is struggling with strabismus, talk to an eye doctor.
Your eye doctor will run tests to diagnose any vision issues and treat them accordingly. Leaving strabismus untreated can cause more sight issues later on.
In this article
All Vision Center content is medically reviewed and fact-checked by a licensed optometrist to ensure the information is factual and meets industry standards.
We have strict sourcing guidelines and only cite from recent scientific research, scholarly articles, textbooks, government agencies, optometry websites, and medical journals.