3DVisionGym Training Guide

An Introduction to Visual Skills and How to Practice Them

This guide is for educational purposes only. It is not medical advice.

Important Disclaimer

Before you begin:

• Talk to an eye doctor first. If you have eye conditions, have had eye surgery, or notice visual symptoms, check with an optometrist or ophthalmologist before starting.
• Stop if it hurts. If you get eye pain, lasting blurred vision, double vision that doesn't go away when you take off the glasses, headaches, dizziness, or nausea—stop using the app. Your eyes don't adapt to training the way muscles do. Persistent discomfort is a warning sign, not a sign of progress.
• This is not therapy. These exercises don't replace professional vision therapy from a trained optometrist or vision therapist.
• Results vary. What helps one person may not help another. Not everyone improves from visual training.
• No guarantees. We make no claims about specific outcomes, performance improvements, or health benefits.
• Age consideration. This application is intended for adults. Children should use 3DVisionGym only under adult supervision and with approval from an eye care professional.

If you have sudden vision changes, get medical help right away—don't rely on this app.

By using 3DVisionGym, you're accepting responsibility for yourself.

What is Sports Vision Training?

Sports vision training is exercise for your eyes—things like tracking, depth perception, reaction time, and getting both eyes to work together. These are skills you use in sports and gaming.

The Research Landscape

A 2024 systematic review examined 126 published studies on vision training for athletes [1]. The review catalogued common training approaches but found significant methodological limitations across the literature. Many studies lacked randomization, placebo controls, blinding, and adequate sample sizes.

Studies consistently find that elite athletes have superior visual abilities compared to non-athletes. However, this correlation does not prove causation. We cannot determine from these studies whether:

• Superior vision enabled their athletic success
• Athletic practice developed their visual abilities
• Individuals with better vision are simply more likely to pursue and succeed in sports

There is also publication bias to consider—negative findings (studies that don't show benefits) are less likely to be published, which may create an overly optimistic picture of the evidence.

Visual Skills in Sports

Consider what your eyes do during sports or gaming:

• Track a moving ball across the field (smooth pursuit)
• Judge distance to catch, hit, or intercept (depth perception)
• Shift focus from near to far and back (vergence)
• Scan the environment for teammates, opponents, or threats (saccadic eye movements)
• Monitor multiple players while maintaining focus (divided attention, peripheral awareness)
• React quickly to visual cues (visual reaction time)

Visual skills matter, but how much depends on the sport and the person. They're one piece alongside motor skills, conditioning, and sport-specific know-how.

Visual Skills Explained

Here are the visual skills you'll practice:

Smooth Pursuit Eye Movements

What it is: The ability to smoothly track a moving object with your eyes, keeping it in focus as it moves.

Why it may matter: When a baseball player tracks a pitch or a tennis player follows a serve, they use smooth pursuit. Smoother tracking may help keep the target in focus.

The research: Athletes tend to show smoother tracking and faster response times than non-athletes. But we don't know if training pursuit on its own improves sports performance. Athletes might have developed smooth tracking through playing their sport, or people with naturally better tracking might just be more likely to become athletes.

Vergence (Convergence and Divergence)

What it is: The coordinated movement of both eyes to focus on objects at different distances.

• Convergence: Your eyes turn inward to focus on something close.
• Divergence: Your eyes turn outward to focus on something distant.

Why it may matter: Shifting gaze between near and far objects requires vergence adjustments. Vergence difficulties can cause fatigue and discomfort.

The research: Vergence exercises work well for treating convergence insufficiency—a condition affecting about 4-8% of people. But fixing a problem is different from improving something that already works fine. There's not much evidence that vergence training helps people who don't have a problem.

(If you see higher figures like 30%, those usually come from studies of people with symptoms, or studies using looser definitions.)

Depth Perception (Stereopsis)

What it is: The perception of depth from combining the slightly different images seen by each eye. Because your eyes are separated by about 2.5 inches, each sees the world from a slightly different angle. Your brain combines these images to create 3D perception.

Why it may matter: Depth perception helps judge distances—relevant for catching, hitting, and navigating.

The research: Pro athletes tend to have better depth perception than amateurs. But these studies can't tell us which came first—did they develop better depth perception by playing, or did their natural depth perception help them become pros?

Some research suggests depth perception can be trained. How much you can improve if yours is already normal? That's unclear.

Saccadic Eye Movements

What it is: Rapid, jumping eye movements that shift your gaze from one fixation point to another.

Why it may matter: When scanning a playing field or shifting gaze from ball to goal, you make saccades.

The research: Athletes in volleyball, baseball, and badminton tend to have slightly faster saccades than non-athletes—typically by tens of milliseconds. Whether these small differences actually matter for performance, and whether training saccadic speed helps athletics, is still unclear.

Peripheral Awareness

What it is: The ability to detect and process visual information from the edges of your visual field while maintaining central focus.

Why it may matter: In team sports, you often watch the ball while being aware of players around you.

The research: Expert athletes seem to have wider functional visual fields. But peripheral vision tests aren't very reliable, and we don't really know how much peripheral awareness matters on the field.

Multiple Object Tracking (MOT)

What it is: The ability to simultaneously track several moving objects.

Why it may matter: In team sports, you rarely focus on just one thing. A midfielder might track ball, teammates, and opponents.

The research: MOT training makes you better at MOT tasks. But evidence that this transfers to actual sports performance is weak—initial studies suggesting better passing decisions haven't been replicated consistently. There may be improvements in working memory, but whether that helps on the field is unclear.

Athletes are better at MOT than non-athletes, but we don't know which way the causation runs.

3DVisionGym Exercises

3DVisionGym includes nine exercises targeting different visual skills. Most use red/cyan anaglyph glasses to create stereoscopic depth effects. A few work without glasses.

Getting Started

Equipment You Need

Red/Cyan Anaglyph Glasses

• Red lens over left eye, cyan over right.
• Standard paper or plastic anaglyph glasses work.
• NOT polarized 3D glasses (like those from movie theaters).

Computer or Tablet

• Modern web browser.
• Larger screens are generally better. Phone form factor will not work well.
• Comfortable lighting.

Calibration

Stereo Separation

Before your first session:

1. Put on your glasses.
2. Select any exercise that uses 3D glasses (like Smooth Pursuits or Convergence).
3. Look for the "Stereo Separation" slider in the control panel on the left.
4. Start at 0.0 and slowly increase until you see clear depth.
5. You should see a single, fused 3D image—not doubled.
6. If you see double, reduce separation until images fuse cleanly.

Suppression Check

To check if both eyes are working together, turn on "Suppression Check" in the control panel. This shows an "L" (red) in the top-left and "R" (cyan) in the top-right of the display. You should see both letters when wearing your glasses. If you only see one, your brain may be ignoring (suppressing) one eye—try blinking rapidly or adjusting lighting. If the problem persists, consider seeing an eye doctor.

Settings Menu

The Settings menu (gear icon) lets you customize your experience:

Cloud Sync
Turn this on to back up your progress to the cloud. Your data syncs automatically after each session—so if you switch devices or clear your browser, your levels and stats come with you. You can also manually sync or delete your cloud data from here.

Game Behavior

• Allow Repeat Targets: When off, the same target position won't appear twice in a row. Some people find this less frustrating.

Display

• Minimal Controls During Training: Hides the sidebar during exercises to give you more screen space. Helpful on smaller screens.

Progress Data
Shows your highest achieved levels for each exercise. This is where you can see your personal bests.

Your Progress Carries Over

Your performance levels carry over between sessions. If you reach level 25 in Convergence training today, you'll start at level 25 tomorrow. The app remembers where you left off—both locally in your browser and (if enabled) in the cloud.

Training Considerations

Research hasn't established the best training schedule. But short, regular sessions are probably easier to stick with than occasional long ones.

Daily Training mode runs you through about 12 minutes of exercises.

Listen to your eyes:

• If you get eye pain, lasting blurred vision, double vision that doesn't go away when you take off the glasses, headaches, or discomfort that sticks around—stop.
• See an eye doctor if symptoms don't clear up.

Working with Professionals

3DVisionGym is for practicing on your own. It's not a substitute for professional care.

When to Seek Professional Help

• If you have an existing eye condition or history of eye problems.
• If you experience persistent discomfort or visual symptoms.
• If you suspect a vision problem.
• If you want a comprehensive vision assessment.
• If you want supervised, customized vision therapy.

Types of Professionals

Developmental Optometrists
Optometrists with extra training in how both eyes work together. They can assess and treat binocular vision problems.

Sports Vision Specialists
Eye doctors who focus specifically on visual performance for athletes.

Vision Therapists
Professionals who deliver vision therapy programs under an optometrist's supervision.

How to Find Qualified Professionals

• COVD (College of Optometrists in Vision Development): covd.org
• ISVA (International Sports Vision Association): sportsvision.pro
• Ask your optometrist for referrals.

What Professionals Provide

• Thorough assessment: They can find problems you don't know you have.
• Diagnosis: They can tell you if something's actually wrong.
• Custom programs: Training designed specifically for you.
• Oversight: Someone watching your progress and adjusting as needed.
• Better equipment: Tools you can't get at home.

Working at home on your own is not the same as working with a professional.

Limitations and Honest Assessment

We want to be clear about what 3DVisionGym is and isn't.

What the Research Shows

• Elite athletes tend to have better visual skills than non-athletes.
• Some visual skills can probably be improved with practice—at least for some people.
• But most studies have methodological problems.
• Whether visual training actually helps you play better is unclear—the evidence is mixed.
• Negative findings (studies that don't show benefits) are less likely to get published, so the research may look more promising than it is.
• Some reviews have concluded there isn't enough evidence to say that vision training improves athletic performance.

What We Don't Know

• How much any given person can improve.
• Whether getting better at these exercises makes you better at your sport.
• How often or how long you should train.
• How long improvements last if you stop practicing.
• Whether people who already have great visual skills can get even better (or if they've already hit their ceiling).

What 3DVisionGym Is

• A way to practice visual skills at home using exercises similar to those used in vision training.
• Easy to use, and accessible.
• A supplement to other training, not a replacement.

What 3DVisionGym Is Not

• A medical device.
• A substitute for professional vision therapy.
• A guarantee of improvement.
• Appropriate for treating eye diseases or medical conditions.
• Equivalent to supervised professional care.

Bottom Line

Will this help you? We don't know. It depends on who you are and what you're starting with.

Here's our advice:

1. Keep expectations realistic.
2. Pay attention to how it feels—you'll learn what works for you.
3. Talk to a professional if you have concerns or specific goals.
4. If you're going to try it, be consistent and give it time.

References