At-Home Convergence Ball Exercise for Kids: Fix Crossed Eyes & Double Vision (Easy Step-by-Step Guide)

Parents of young kids—let’s talk: Does your child squint nonstop, rub their eyes until they’re red, complain about blurry vision, or say they “see two of everything”? Do their eyes look slightly crossed, or do they skip lines/mix up words when reading? If yes, they might be dealing with eye fusion dysfunction—a common issue where their eyes struggle to work together to form one clear image.

The good news? You don’t need fancy clinic equipment to help. Bolin Eye Clinic shares a simple at-home fix: the convergence ball exercise. It’s easy, kid-friendly, and targets the root of crossed eyes, double vision, and eye strain. Let’s dive in.

What Is a Convergence Ball? (And Why It Works for Kids)

A convergence ball set is just three colored balls (usually red, yellow, green) strung on a string—but it’s a powerhouse for training your child’s eyes to “sync up.” No store-bought set? No problem: A simple string with three small balls (like ping pong balls painted red/yellow/green, or even small toy balls) works just as well.

How It Helps Your Kid’s Eyes

This exercise targets three key skills their eyes need to work together:

Convergence training: Teaches both eyes to turn inward (slightly) to focus on close-up objects (like the nearest ball)—a must for reading, coloring, or using tablets.

Divergence training: Helps eyes relax and turn outward to focus on faraway objects (like the farthest ball)—great for looking at whiteboards or playing outside.

Flexibility training: By switching focus between near/far balls, it’s like “eye cardio”—building stamina so their eyes don’t get tired as easily.

Who This Helps Most

It’s ideal for kids with:

Mild exophoria (eyes drift outward when focusing close-up, even if it’s not obvious).

Intermittent strabismus (crossed eyes that come and go, like when they’re tired).

Insufficient convergence (they struggle to hold objects close to their face and focus).

Fusion dysfunction (double vision or blurriness when switching between near/far tasks).

Step 1: Set Up the Convergence Ball (3 Minutes Max!)

You’ll need:

3 small balls (red, yellow, green—bright colors help kids focus).

A 3–4 foot (1–1.2 meter) string.

Tape (masking tape works best) to secure the string.

A plain wall (no busy patterns—so the balls stand out).

How to Hang It

String the balls: Tie one end of the string to a doorknob or tape it to a wall at your child’s eye level. Thread the three balls onto the string, then tie the other end to a small handle (or hold it yourself—just keep it taut).

Set distances (measure from your child’s nose):

Green ball (farthest): 3 feet (90cm) away.

Yellow ball (middle): 12 inches (30cm) away.

Red ball (closest): Start at 1 inch (2.5cm) from their nose (you can adjust later!).

Check height: The string should line up with your child’s brow bone—they shouldn’t tilt their head up/down to see the balls.

Step 2: 3 Convergence Ball Exercises (Kid-Friendly!)

Start with 2–3 sessions a day, 10 minutes each. Let your kid take breaks if their eyes feel tired—fun > forcing it!

1. Basic Focus Training (For Beginners)

This builds foundational eye coordination:

Have your child stand 3 feet (90cm) from the wall, facing the string.

Tell them to stare at the red ball (closest) for 5 seconds. They should see:

1 clear red ball.

2 yellow balls and 2 green balls (out of the corner of their eyes).

The string should look “crossed” at the red ball (this is normal!).

Switch to the yellow ball (middle) for 5 seconds. Now they’ll see:

1 clear yellow ball.

2 red balls and 2 green balls.

String crossed at the yellow ball.

Switch to the green ball (farthest) for 5 seconds. Repeat the same check.

Progress: Each session, move the red ball 2 inches (5cm) closer to their nose (until it’s 1 inch/2.5cm away). Do this 10 times per session.

2. Jump Training (For Kids Who Master the Basics)

This boosts speed and flexibility:

Reset the balls: Red ball at 1 inch (2.5cm) from their nose; yellow ball at 3 feet (1 meter) away.

Tell them to quickly switch focus between the red and yellow balls—hold each for 5 seconds.

Repeat 20 times. Encourage them to say “clear!” each time they lock onto a ball (makes it a game!).

3. Advanced Independent Training (No Balls Needed!)

Once they’re confident, challenge them to train without the string:

Have your child stand still, no string/balls in front of them.

Tell them to slowly move their gaze from 3 feet (1 meter) away to 1 inch (2.5cm) from their nose—like they’re following an imaginary ball.

Key rule: They must see “X-shaped double vision” the whole time (like two crossed strings in their peripheral vision). This means their eyes are working together correctly.

Critical Tips to Keep Training Safe & Effective

Always start with a doctor’s visit: If your child has obvious crossed eyes, double vision, or vision problems, take them to a pediatric ophthalmologist first. Only a doctor can confirm if this exercise is right for them (it won’t work for severe strabismus!).

Skip unsupervised training if your kid has:

High myopia (nearsightedness).

Anisometropia (a big prescription difference between their two eyes).

Recently had cataract surgery.

Always follow your doctor’s advice here.

Signs it’s working: The ball they’re focusing on is clear and single; peripheral balls look double (normal!). If they get persistent double vision, dizziness, or eye pain—stop immediately and call the doctor.

Take it slow: Start with 2–3 minutes per session, then extend as they get comfortable. Aim for 4–5 days a week (consistency beats long sessions!).

Be patient: It takes at least 3 months of regular training to see steady improvements. Don’t quit if you don’t see changes in the first few weeks!

Final Reminder for Parents

Crossed eyes or double vision aren’t “just a phase”—they can affect your child’s reading, learning, and even self-esteem if left unaddressed. But at-home exercises like the convergence ball can help—only if you first get a professional diagnosis.

Never try to “fix” suspected strabismus on your own. A pediatric ophthalmologist will create a plan tailored to your kid’s needs, and this exercise can be part of that plan (not a replacement for medical care).

With a little consistency and guidance, your child’s eyes will learn to work together—and those squints, rubs, and “two of everything” complaints will become a thing of the past!