Visual suppression happens when the brain gives less weight to visual information from one eye while both eyes remain open. It often develops when the two eyes send unequal or conflicting visual input. This pattern can occur with conditions such as amblyopia and strabismus.
Because suppression happens within the visual system, a person may not notice it. In some cases, the brain uses suppression to reduce confusing or competing visual information.
Understanding this process helps patients and parents see an important point. Good vision depends on more than clear sight in each eye.
Table of contents
- What Is Visual Suppression?
- Why Does Suppression Happen?
- Suppression, Amblyopia, and Strabismus
- Can You Tell If One Eye Is Being Suppressed?
- How Is Suppression Tested?
- How Is Suppression Addressed?
- How Does AmblyoPlay Use Dichoptic Training?
- Why Understanding Visual Suppression Matters
- Frequently Asked Questions: Visual Suppression
What Is Visual Suppression?
Each eye views the world from a slightly different angle. The brain normally combines information from both eyes to create a stable, unified view. This coordinated use of the two eyes supports binocular vision.
With visual suppression, the brain reduces the influence or awareness of information from one eye during binocular viewing. Researchers often call this interocular suppression when they describe an imbalance between the two eyes.
Suppression does not mean that one eye simply “switches off” or stops seeing. The eye can still receive and process visual information.
The amount of suppression can also vary. In some people, it affects only certain areas of the visual field rather than the whole view.
In strabismus, for example, the brain may suppress visual information from specific retinal areas to reduce conflicting images. Clinicians sometimes describe these areas as suppression scotomas.
Why Does Suppression Happen?
Comfortable binocular vision depends on the brain receiving visual information that it can combine successfully.
Problems can develop when the two eyes provide very different input. Strabismus may point the eyes in different directions.
A large difference in refractive error can also make one eye’s image much blurrier than the other. Clinicians call this difference anisometropia.
When the brain receives conflicting binocular information, it may give less weight to one eye’s input. In strabismus, this response can reduce visual confusion or double vision.
However, it can also limit normal binocular cooperation.
Suppression, Amblyopia, and Strabismus
Suppression and amblyopia are closely related, but they are not the same condition.
Amblyopia is a neurodevelopmental vision disorder. It can develop when something disrupts normal visual development, usually during childhood. Over time, the brain may rely more heavily on the stronger eye and use less information from the weaker eye.
Modern research also views amblyopia as a binocular disorder, not only as reduced visual acuity in one eye. Interocular imbalance, suppression, reduced stereopsis, and other binocular deficits can all play a role.
Suppression also commonly occurs with strabismus. When the eyes do not align, each eye may direct its central vision toward a different location. The brain may then reduce the influence of conflicting information from one eye to avoid persistent double vision.
The relationship is complex. Suppression, amblyopia, and strabismus can interact during visual development. A single cause-and-effect explanation does not describe every case.
Can You Tell If One Eye Is Being Suppressed?
Not always.
Suppression can be difficult to notice because it may reduce an otherwise confusing visual experience. A person who suppresses input from one eye may not experience obvious double vision.
Reduced binocular function may instead affect stereopsis and depth perception. However, difficulty with depth perception does not automatically mean that suppression is present.
Children may be especially unlikely to notice a binocular vision problem. Their visual system may have developed that way, so they have no different visual experience for comparison.
Symptoms alone cannot reliably confirm suppression. An eye care professional needs to assess how the two eyes work together.
Free Vision Therapy Guide!
- Brochure with 5 Simple Eye Exercises:
These exercises are easy to perform and can help enhance your visual skills and reduce eye strain. - Exclusive Video:
Watch a comprehensive video explanation of vision therapy by Erin Jubas, a vision therapist. Learn how vision therapy works and its benefits for various vision conditions. - Convergence Card:
Get a convergence card for training your vision skills. Make sure to print it both-sided!
How Is Suppression Tested?
Eye care professionals can assess suppression as part of a broader binocular vision evaluation.
One common clinical test is the Worth 4 Dot test. It helps the clinician determine whether a person uses both eyes together, suppresses one eye, or experiences double vision. Clinicians may also use Bagolini lenses, the 4-prism-diopter base-out test, stereopsis tests, and other sensory binocular vision assessments.
Each test provides different information. The clinician interprets the results together with the rest of the examination. No single test measures suppression perfectly in every person or situation. Research and clinical practice use several methods to detect or quantify it.
Clinicians therefore interpret suppression within the full binocular vision picture rather than as a standalone finding.
How Is Suppression Addressed?
The best approach depends on why suppression occurs. The clinician also considers the person’s diagnosis, age, visual acuity, eye alignment, refractive correction, and binocular function.
For amblyopia, treatment may include appropriate glasses or contact lenses, patching of the fellow eye, or atropine penalization. The exact plan depends on the individual case.
Clinicians may also use binocular and dichoptic treatment approaches.
Dichoptic training presents different but complementary visual information to each eye while both eyes remain open. The goal is to encourage both eyes to participate in the visual task. This can support more balanced binocular processing.
This approach can be especially relevant when suppression and reduced binocular cooperation form part of the visual problem. Instead of simply covering one eye, dichoptic training engages both eyes at the same time. It also controls what each eye sees.
How Does AmblyoPlay Use Dichoptic Training?
AmblyoPlay applies the principles of dichoptic training through binocular exercises. These exercises present selected visual elements separately to each eye.
AmblyoPlay specialized red-green glasses help each eye receive different visual information while both eyes stay open and engaged in the same activity. The exercises encourage both eyes to participate and work together instead of relying mainly on one eye’s input.
This approach can be particularly relevant when visual suppression or an imbalance between the two eyes contributes to the problem.
AmblyoPlay combines this approach with interactive, game-based exercises that can be completed at home as part of a vision therapy program. The training can therefore provide a more engaging way to practice binocular visual skills between visits with an eye care professional.
Why Understanding Visual Suppression Matters
Visual suppression highlights an important point: clear sight in each eye is only one part of good vision. The brain must also use and combine information from both eyes effectively.
Suppression can occur alongside amblyopia, strabismus, and other binocular vision problems. A person may not notice it. That makes binocular vision assessment important when concerns arise about how the eyes work together.
Understanding the presence and cause of suppression can help an eye care professional choose the most appropriate treatment approach.
If you or your child has concerns about binocular vision, eye alignment, depth perception, or amblyopia, talk to an eye care professional. They can assess how the two eyes work together and recommend the next steps.
Sign up for our newsletter and save 10%!
Subscribe to AmblyoPlay with 10% discount! By subscribing to our newsletter you will receive helpful tips, insightful content, and latest news from the field of vision therapy and improving our most precious sense: sight!
Frequently Asked Questions: Visual Suppression
What is visual suppression?
Visual suppression happens when the brain reduces the influence of visual information from one eye while both eyes are open. It can occur when the two eyes provide unequal or conflicting input and may affect how effectively they work together.
Is visual suppression the same as amblyopia?
No. Visual suppression and amblyopia are related, but they are not the same thing. Amblyopia is a neurodevelopmental vision disorder, while suppression describes how the brain may reduce the influence of input from one eye during binocular viewing. Suppression can form part of the binocular imbalance seen in amblyopia.
Can you tell if one eye is being suppressed?
Not always. Suppression may actually reduce symptoms such as visual confusion or double vision, which can make it difficult for a person to notice. Problems with binocular vision, stereopsis, or depth perception may occur, but an eye care professional needs to assess the visual system to determine whether suppression is present.
How do eye care professionals test for visual suppression?
Eye care professionals can evaluate suppression as part of a binocular vision examination. Tests may include the Worth 4 Dot test, Bagolini lenses, stereopsis testing, and other sensory binocular vision assessments. Clinicians interpret these results together with the rest of the eye examination.
Can visual suppression be addressed with vision therapy?
The appropriate treatment depends on the underlying condition and the individual’s visual function. Some treatment plans may include binocular or dichoptic training, which keeps both eyes open while presenting controlled visual information to each eye. This approach aims to encourage both eyes to participate and work together, and tools such as AmblyoPlay can incorporate dichoptic exercises as part of a vision therapy program.
