Rethinking Amblyopia Treatment: Beyond the Eye Patch

Amblyopia is one of the most common causes of reduced vision in children. Traditionally, treatment has focused on making the weaker eye work harder by limiting the visual input from the stronger eye. This has primarily been done by patching the stronger eye or using atropine drops to temporarily blur the vision of the stronger eye.

These treatments can be very effective—and they are still important tools in amblyopia management. However, our understanding of amblyopia has evolved. Rather than viewing amblyopia as simply a problem with one eye, researchers and clinicians increasingly recognize that it is a neurodevelopmental disorder involving the way the brain processes information from both eyes.

This shift has led to interest in a different approach: binocular or dichoptic therapy, which attempts to train the two eyes to work together rather than simply suppressing the stronger eye.

What Is Amblyopia?

Amblyopia develops when the brain does not receive or properly process clear, balanced visual information from the two eyes during visual development. Common causes include strabismus, anisometropia, and significant refractive error.

When one eye consistently provides a better-quality image, the brain may begin to favor that eye and suppress information coming from the weaker eye. Over time, the visual pathways associated with the amblyopic eye do not develop normally. For this reason, simply placing glasses on a child does not always completely resolve the problem. Glasses may help to balance the eyes or provide more relief between the eyes, but the brain may still favor the previously dominant eye.

Why Do We Patch?

Patching is more of a traditional approach and fairly straightforward. Simply put, if the brain is relying too heavily on the stronger eye, temporarily take that eye out of the equation. Patching the stronger eye forces the child to use their “weaker”, or amblyopic eye, for visual tasks.

Atropine works somewhat differently. Instead of physically covering the stronger eye, atropine temporarily relaxes accommodation (focusing system) and blurs the vision of the better-seeing eye. This encourages greater use of the amblyopic eye.

Research has demonstrated that these treatments work. In fact, studies comparing patching and atropine have generally found similar improvements in visual acuity. A Cochrane review concluded that both conventional patching and atropine penalization improve visual acuity in children with amblyopia.

So why look for something different?

The Limitations of a Monocular Approach

The biggest limitation of patching and atropine is that they primarily encourage monocular use. Normal vision, however, is inherently binocular. We rely on both eyes simultaneously for depth perception, perceive three-dimensional space, maintain visual stability, and integrate information from slightly different perspectives.

So, what if instead of suppressing the stronger eye, we could teach the brain to use both eyes together?

The goal is not simply to make the amblyopic eye stronger. It is to encourage the brain to accept and combine information from both eyes to promote equal visual input.

Here’s Where We Introduce Red/Green Binocular Therapy

One method of binocular treatment uses red/green glasses while viewing specially designed computer programs, games, or videos.

The screen presents different visual information to each eye. The purpose of the red/green glasses is for one eye to see one image and the other eye to see another at the same time to promote binocularity. The amblyopic eye may receive a clear image, while the fellow eye receives a lower-contrast version of certain elements. 

Instead of allowing the stronger eye to completely dominate, the treatment attempts to reduce suppression and encourage binocular combination. The child must use information from both eyes to successfully perceive the image or complete the task. For example, if the child is using their device and all of a sudden the screen turns black, this indicates that the weaker eye has “turned off”. The filter over the stronger eye essentially cancels out the filter over the device creating a black screen.

To explain it simply:

With patching - One eye works while the other eye is covered.

With binocular therapy - Both eyes work which means the brain is encouraged to combine their information.

Why Use a TV or Screen?

Rather than asking a child to stare at an eye chart or perform repetitive exercises, treatment can incorporate activities that are naturally engaging—such as watching cartoons, movies, or playing games.

Compliance matters.

A child may resist wearing an eye patch for several hours every day. Asking that same child to watch their favorite show while wearing red/green glasses may feel much less like treatment.

Interestingly, the article Amblyopia and Binocular Vision also discusses treatment adherence and the limitations of traditional therapy. Although patching is effective, not every child achieves normal visual acuity, and compliance can influence treatment outcomes.

The Future May Be Binocular

The most exciting part of this research may not be determining whether binocular therapy is “better” than patching. It may be recognizing that different treatments target different aspects of amblyopia.

Patching and atropine are excellent at reducing the dominance of the fellow eye and improving visual acuity in the amblyopic eye. Binocular therapy takes a different approach by attempting to reduce suppression and improve the brain's ability to use information from both eyes simultaneously.

Perhaps the future of amblyopia treatment is not: Patching OR binocular therapy.

Instead, it may be → Optical correction + binocular rehabilitation and individualized monocular treatment.

Brianna Opalewski

Chicago College of Optometry

C/O 2027

References

1. Birch EE, et al. Amblyopia and binocular vision. Progress in Retinal and Eye Research. 2012.

2. Li T, Qureshi R, Taylor K. Conventional occlusion versus pharmacologic penalization for amblyopia. Cochrane Database of Systematic Reviews. 2019.

3. American Academy of Ophthalmology. Binocular Treatment of Amblyopia: A Report by the American Academy of Ophthalmology. Ophthalmology. 2020.

4. Home use of binocular dichoptic video content device for treatment of amblyopia: a pilot study. Journal of AAPOS. 2018.

5. Patch-free streaming contrast-rebalanced dichoptic cartoons versus patching for treatment of amblyopia in children aged 3 to 5 years: a pilot, randomized clinical trial. Journal of AAPOS. 2024.