Dichoptic vision therapy treats amblyopia by showing each eye a different image, often with the stronger eye’s image dimmed. To complete the task, the brain has to combine input from both eyes. With repetition, this reduces suppression and strengthens binocular connections in the visual cortex.
How can playing a game with coloured glasses change the way the brain sees? It sounds surprising, but it is exactly what dichoptic vision therapy is designed to do. Amblyopia, or lazy eye, begins in the brain, so effective vision therapy for amblyopia needs to work where the problem starts.
What Is Dichoptic Vision Therapy?
Dichoptic vision therapy is a type of binocular treatment in which each eye is shown a separate image at the same time, so that the brain must use both eyes together.
The word itself explains the idea. “Di” means two, and “optic” relates to the eyes, so dichoptic simply means two separate views. Traditional monocular approaches, such as patching, cover the stronger eye so the weaker eye has to work alone. Dichoptic therapy keeps both eyes open and trains them as a team.
This binocular approach is central to modern vision therapy for amblyopia, including Bynocs amblyopia therapy, which is prescribed and monitored by eye care professionals.
Why Amblyopia Is a Brain Problem, Not Just an Eye Problem
In most cases of amblyopia, the eye itself is healthy. The real issue is that the brain has learned to ignore it.
During early childhood, a period often called the critical period, the visual cortex learns how to combine the images from both eyes into one. The brain starts to favour the clearer eye if the other eye sends:
- a blurry image, because of a prescription difference (anisometropia)
- a misaligned image, because of a squint (strabismus)
To avoid confusion or double vision, the brain then switches off much of the weaker eye’s signal. This process is called suppression. Over time, suppression becomes a habit, and the weaker eye’s vision fails to develop fully, even with glasses.
Amblyopia is common. The US National Eye Institute estimates that it affects as many as three percent of children. Because the root cause lies in how the brain processes vision, treatments that retrain the brain are an important part of care.
How Dichoptic Therapy Retrains the Brain, Step by Step
Step 1: Splitting the Image Between the Eyes
Special glasses or a headset make sure each eye sees a different part of the same game or activity. For example, the weaker eye may see the moving targets, while the stronger eye sees the background or the player’s controls. Neither eye has the full picture on its own.
Step 2: Rebalancing the Input
This is the key idea behind dichoptic therapy. In amblyopia, the stronger eye dominates so heavily that the brain overlooks the weaker eye. To level the playing field, the image shown to the stronger eye is made dimmer or lower in contrast. This is known as contrast rebalancing. With the stronger eye’s signal turned down, the weaker eye’s signal finally gets the brain’s attention.
Step 3: Forcing Binocular Combination
Because each eye holds only part of the information, the brain cannot succeed by relying on one eye. It must combine input from both eyes to play the game. Each successful move is a moment of true binocular vision, which the brain has not practised properly before.
Step 4: Repetition Drives Neuroplasticity
The brain changes through repeated practice, a process called perceptual learning. Each session repeats thousands of small binocular tasks. Over weeks, this strengthens the neural pathways that link both eyes in the visual cortex and weakens the habit of suppression.
Step 5: Gradually Restoring Balance
As the weaker eye improves, the difference between the two images is slowly reduced. The goal is for the brain to accept both eyes equally, even without any rebalancing.
How Are Dichoptic Images Created?
| Method | How it separates the images | Where it’s used |
| Anaglyph glasses | Coloured lenses (such as red and green) filter different colours to each eye | Computer-based home therapy |
| Polarised filters | Polarised lenses match a polarised screen | Clinics and some 3D displays |
| VR headsets | A separate screen for each eye | Home and clinic |
| Shutter glasses | Lenses rapidly alternate which eye sees the screen | Specialised setups |
Bynocs uses anaglyph glasses with a computer, which keeps the setup simple for use at home.
Dichoptic Therapy vs Patching: Two Different Approaches
Patching makes the weaker eye work by covering the stronger eye. Dichoptic therapy trains both eyes to work together while both stay open.
| Patching (occlusion therapy) | Dichoptic therapy | |
| Eyes open | One | Both |
| Main goal | Strengthen the weaker eye | Strengthen the weaker eye and binocular vision |
| Format | Wearing a patch for set hours | Interactive activities |
Patching remains an established treatment for amblyopia, and some treatment plans combine both approaches. Your eye care professional will decide what suits you best. To see how these methods fit into the wider picture of vision therapy for lazy eye, read how vision therapy helps improve lazy eye and visual skills.
How Bynocs Uses Dichoptic Therapy
Bynocs is a cloud-based platform that delivers dichoptic therapy through specially designed games. Patients play on a computer while wearing anaglyph glasses, and a typical session lasts about 30 minutes.
Here is how Bynocs applies the science:
- Contrast rebalancing: The stronger eye sees a dimmer image, encouraging the brain to use the weaker eye.
- AI-based adaptive difficulty: Games adjust contrast, size, and speed as performance improves.
- Engaging design: The game format helps children stay consistent, which is essential for neuroplasticity.
- Remote monitoring: Session data and eye tracking results are shared with the eye care professional, who can fine-tune the plan.
This makes online vision therapy for amblyopia practical for daily use, without frequent clinic visits.
Curious whether dichoptic therapy could help you or your child? Talk to the Bynocs team.
What Does Research Show About Dichoptic Therapy?
Dichoptic therapy with Bynocs has been evaluated in peer-reviewed studies:
- 161 children aged 4–13: After a 30-minute, 5-days-a-week, 6-week protocol, the weaker eye improved by an average of 0.39 logMAR. Binocular function also improved significantly.
- 23 children aged 5–15: After 30 home sessions, visual acuity in the amblyopic eye improved from 0.28 to 0.13 logMAR on average.
logMAR is the scale eye doctors use to measure clarity, and lower numbers mean better vision. A change of 0.1 is roughly one line on an eye chart, so 0.39 is close to four lines.
Individual results vary with age, cause, and consistency. For a skill-by-skill breakdown, see whether Online Vision Therapy for Lazy Eye can improve visual skills.
Myths vs Facts About Dichoptic Therapy
Myth: It only works for young children.
Fact: Children often respond faster, but neuroplasticity continues into adulthood, and adults can also benefit. Learn more about lazy eye treatment in adults.
Myth: It’s just playing video games.
Fact: The games are designed for therapy. They are prescribed, adjusted, and monitored by an eye care professional.
Myth: It replaces glasses.
Fact: Glasses give the brain the clear image that dichoptic therapy builds on, so they usually remain part of the plan.
Can Home Exercises Support Dichoptic Therapy?
Yes, when your eye care professional recommends them. Lazy eye training exercises such as near-far focusing and Brock string practice can support binocular skills between sessions. They complement dichoptic therapy but don’t replace it. See our guide to 7 at-home lazy eye training exercises.
Who Is Dichoptic Therapy Suitable For?
Dichoptic therapy is often considered for anisometropic amblyopia and some cases of strabismic amblyopia, after a professional assessment. A large or constant squint, a cataract, or other eye diseases may need clinical treatment first or alongside therapy.
Starting Dichoptic Therapy at Home
A home-based program usually follows four steps:
- an eye assessment
- setup with a computer and anaglyph glasses
- short daily sessions
- regular progress reviews
For a week-by-week walkthrough, read what to expect from an online amblyopia vision therapy program.
Frequently Asked Questions
What is dichoptic vision therapy in simple words?
It is a treatment where each eye sees a different image at the same time. The brain has to use both eyes together to complete the task, which helps retrain binocular vision.
Why does the stronger eye see a dimmer image in dichoptic therapy?
Dimming the stronger eye’s image reduces its dominance. This balances the input, so the brain pays attention to the weaker eye instead of suppressing it.
Is dichoptic therapy better than patching?
They work differently. Patching covers the stronger eye, while dichoptic therapy trains both eyes together. Your eye care professional may use one or both, depending on your needs.
Does dichoptic therapy work for adults?
Adults can benefit, because the brain keeps some neuroplasticity throughout life. Progress may be slower than in children, and an assessment helps set realistic goals.
How long does dichoptic therapy take to show results?
Many programs run for about 30 sessions over 6 weeks. Some people notice changes earlier, while others need a longer course. Progress is checked at regular reviews.
Is dichoptic therapy safe for children?
When it is prescribed and monitored by an eye care professional, dichoptic therapy is generally considered safe for children. It is non-invasive, with short, structured sessions.
Retrain Both Eyes to Work Together With Bynocs
Dichoptic vision therapy works by splitting the image, rebalancing the input, forcing the eyes to combine, and repeating until the brain restores balance. Bynocs brings this research-backed approach home with AI-based games, anaglyph glasses, and professional monitoring.