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Amblyopia Symptoms: How to Tell if You Have a Lazy Eye

The symptoms of amblyopia.

Amblyopia symptoms aren't always easy to detect, unlike many other vision problems. If you're wondering how to tell if you have amblyopia – the medical term for what some call a “lazy eye” – we'll share typical symptoms, as well as the best way to diagnose the condition.

Amblyopia, or lazy eye, occurs when clear eyesight fails to develop in one or both eyes.

While impaired eyesight is often the most obvious problem of amblyopia, the underlying cause is poorly developed binocular vision. Normal binocular vision occurs when both eyes see similarly, and the brain can easily combine images produced by each eye into a single, 3D image.

However, when the brain cannot effectively combine the two images, it typically suppresses, or “turns off,” the image from one eye, resulting in reduced eyesight in that eye.

When this condition cannot be improved with glasses and is not caused by disease, we call it amblyopia.

Lazy Eye Symptoms: Detecting Amblyopia Can Be Difficult

Amblyopia is a leading cause of childhood vision loss.


According to the American Optometric Association, amblyopia affects 2 to 4 percent of children and is a leading cause of childhood vision loss.

Amblyopia often begins in infancy and can be challenging to identify outside of a comprehensive eye exam. Children with amblyopia may not even realize their vision is functioning abnormally because they have no frame of reference to judge their vision against.

Abnormal Eye Appearance NOT a Typical Symptom

What does a lazy eye look like? Unfortunately, simple observation alone is usually not enough to detect amblyopia. In fact, the term “lazy eye” inaccurately suggests that the eye doesn’t move, or appears to do what it wants, or is visibly “lazy” in some other way.

But that’s generally not the case.

Unlike strabismus, or “crossed eyes,” in which an eye may be visibly turned in, out, up, or down, amblyopia can’t be diagnosed by an eye’s appearance. While a person can have amblyopia as a result of strabismus, not all cases of amblyopia involve strabismus.

For reasons like these, amblyopia can be difficult for parents to detect. That said, there are a handful of possible indicators.  

Trouble With Depth Perception

Since amblyopia prevents or greatly impairs binocular depth perception,  children with the condition can: 

  • Have pronounced difficulty catching objects
  • Seem clumsy and frequently bump into objects, walls and other people
  • Misjudge the proximity of another person when conversing 

Sure, children are clumsy as they’re growing into their bodies, but keep an eye out for clumsiness beyond the norm. And if your child is resistant to playing catch, usually a natural source of fun for kids, then amblyopia could be the culprit.

Difficulty in School

Amblyopia and reading difficulties can go hand in hand. The condition can affect children’s school performance, causing them to: 

  • Struggle when identifying letters and learning to read
  • Read more slowly than normal
  • Have delayed focus when looking up at the board

Problems with Viewing 3D Movies

If a person has amblyopia, even the special glasses worn to watch a 3D movie will not stop the brain from suppressing the signal from the amblyopic eye. That means just one eye is engaged – and thus no cool 3D effects will be jumping off the screen toward the viewer.

In mild cases of amblyopia, the brain may try to use both eyes with the 3D glasses on. Since the two eyes don't work together well (which is an eye teaming problem), the person could experience adverse effects like dizziness, headaches, and nausea when viewing a 3D. 

Either way, it’s a less-than-blockbuster experience.

Diagnosis: Definitively Identifying Amblyopia Is Possible 

Amblyopia is easily detected with a Functional Eye Exam, which is why it’s extremely important for children to be seen for an exam from the first year of life onward.

Regular eye exams are important.

Remember, children with amblyopia can’t necessarily report their own symptoms. 

They assume everyone sees the world as they do, even though amblyopia may be causing the two eyes to see very differently. They don’t realize that the two eyes should see almost the same. There’s no way they can compare a properly functioning visual system to their own. 

Treatment: Ways to Treat Amblyopia Have Improved

Conventional methods to treat amblyopia include prescribing glasses and then covering, or “patching,” the non-amblyopic eye to improve the eyesight in the amblyopic eye.

While patching can be effective in improving a person’s eyesight (and there is a difference between eyesight and vision), it’s only addressing a small part of the much larger problem: poor development of binocular vision. 

Vision therapy with patching is more effective.

It’s no surprise, then, that studies have shown combining vision therapy with patching is a more effective treatment for amblyopia than just patching alone.

Vision therapy addresses the larger problem by training the brain to use both eyes in order to develop normal binocular vision.

Learn more about types of amblyopia and treatments.

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Posted by   The Vision Therapy Center, Reviewed by Dr. Kellye Knueppel

The content in this post created was written by professional writers and then reviewed and edited for medical accuracy by Dr. Kellye Knueppel of The Vision Therapy Center.   Learn more about Dr. Knueppel's medical background