Vergence Exercises: Fusional, Jump and Prism Vergence

Updated 2026-10-25

Written by the Optics Trainer team from published research, with every source linked below.

Vergence exercises practice turning the two eyes in toward each other (convergence) and back out (divergence) while keeping one single image. They are used most for convergence insufficiency, and also studied in intermittent exotropia and healthy adults. This guide explains what vergence and fusional vergence are, the main kinds of fusional vergence exercises (prism, jump, vectogram and computer), what studies found beyond convergence insufficiency, and how Optics Trainer's eye teaming games are modeled on these tasks.

What is vergence? Convergence, divergence and fusional vergence

Vergence is the movement of the two eyes in opposite directions. When you look at something close, both eyes turn in: that is convergence. When you look back into the distance, they turn out: that is divergence. Our guide to binocular vision and eye teaming explains how vergence fits with focusing and eye movements.

Fusional vergence is the part of this system that keeps the two eyes locked on the same target. EyeWiki, the American Academy of Ophthalmology's clinical wiki, describes it as using feedback from the slight difference between the two eyes' images to keep the eyes aligned. The amount of extra turning in or out you can do before a target doubles is called your fusional vergence range, or fusional reserve. Positive fusional vergence is the convergence side; negative fusional vergence is the divergence side.

Sudden double vision, eye pain, vision loss or symptoms after a head injury need a doctor promptly, not exercises. If headaches, eye pain or double vision appear during an exercise, stop and call your clinician.

How clinicians measure fusional vergence

Fusional vergence ranges are usually measured with prisms of increasing strength, often a prism bar, while you look at a target and report when it blurs, doubles and becomes single again. In the Convergence Insufficiency Treatment Trial, one entry criterion was low positive fusional vergence: failing Sheard's criterion, or blur or break at 15 prism dioptres or less on a prism bar. Eye care professionals can read our clinic article on fusional vergence ranges.

Vergence facility is a related test of speed. A 1998 study defined it as how many times a minute a person can regain a single image while a flip prism alternates between base-in and base-out. In 40 adults, a 3 base-in/12 base-out flipper at near separated those with and without symptoms best.

Fusional vergence exercises: prism, jump, vectogram and computer

Vergence exercises use the same tools as the tests, but repeat them with the demand raised in small steps. Common types include:

Prism vergence exercises: you look through base-out prisms, which make you converge to keep the target single, or base-in prisms, which make you diverge. EyeWiki describes base-out prism work this way. Prism bars step the demand up gradually.
Jump vergence exercises: you switch quickly between two demands, for example with flip prisms or by looking between near and far targets. EyeWiki lists jump convergence among home convergence exercises, and the 1998 facility study used the same alternating flip prisms as a test.
Vectograms, tranaglyphs, the aperture rule and eccentric circles: polarized, red-green or printed targets that show each eye its own picture, so the demand can change while you keep it single. The CINAPS trial in adults listed vectograms, the aperture rule, eccentric circles and computer orthoptics among its techniques.
Computer orthoptics: software that shows random dot stereograms or two-picture targets and raises the demand as you succeed. EyeWiki notes these programs need both eyes aimed at the target.
Convergence and divergence exercises at home, such as pencil push-ups and the Brock string: our guides to convergence insufficiency exercises and the Brock string cover these, so they are not repeated here.

Vergence exercises for convergence insufficiency: a summary

Most vergence eye exercise trials studied convergence insufficiency. The children's trials, including the Convergence Insufficiency Treatment Trial and its reading follow-up, are covered in our guide to convergence insufficiency exercises.

Two randomized trials studied young adults. In a 2005 trial of 46 adults aged 19 to 30, only office-based therapy brought the near point of convergence closer (12.8 cm to 5.3 cm) and raised positive fusional vergence (11.3 to 29.7 prism dioptres). Symptoms improved in all three groups: 42% of the office group, 31% of the placebo group and 20% of the pencil push-up group no longer met the symptom criteria.

In the 2020 CINAPS trial, 50 adults aged 18 to 32 had 12 one-hour office sessions of real or placebo therapy. The near point improved by 6.0 cm with therapy and 3.1 cm with placebo, and positive fusional vergence rose by 17.3 versus 7.4 prism dioptres. Symptom scores improved by a similar amount in both groups, and the authors recommended revising the symptom survey for future trials.

Vergence training beyond convergence insufficiency

Vergence and fusion exercises are also used for intermittent exotropia, an eye that sometimes drifts outward, including the divergence excess type, where the drift is larger at distance. A 2021 Cochrane review of intermittent exotropia found six randomized trials with 890 participants. They compared types of surgery, patching against observation and prism adaptation before surgery; none tested vergence exercises. A 2024 review by Ma and Scheiman said there is no consensus on managing intermittent exotropia and listed vision therapy and orthoptics among the non-surgical options.

Other studies, including trials since then, are summarized below. For convergence excess, where the eyes turn in too much at near, a 2016 review by Ehrt describes bifocal glasses or surgery, and we did not find a controlled trial of vergence exercises.

Studies of vergence training beyond convergence insufficiency
Study	Design	Who	Training	Result as reported
Daum 1984	Retrospective case series	18 people with divergence excess, mean age 15.8	Orthoptics, mean 5.2 weeks	Positive vergences and, slightly, the distance angle changed; negative vergences, near point and stereo did not change
Ma 2024 and 2025	Randomized, examiner-masked, one centre	40 children aged 6 to 17 with intermittent exotropia	Office vergence and anti-suppression therapy vs observation	Better distance control score at 17 weeks (75% vs 25% improved by 1 point or more); larger fusional ranges and vergence facility. Authors called for a full-scale trial
Hedayati 2025	Randomized, 3 groups	53 children and teens aged 5 to 18 with intermittent exotropia	Office and home orthoptic training, with or without a video game, vs part-time patching	Fusional vergence, stereo, near point and distance control improved more with training
Jing 2026	Randomized, 3 hospitals	177 children aged 6 to 18 with intermittent exotropia	12 weeks of home virtual reality vision therapy vs observation	Control score difference of 0.33 points; authors called it modest, with larger change in those who trained most

Vergence adaptation and learning in healthy adults

Researchers have also asked whether vergence changes with practice in people with normal binocular vision. Short-term vergence and prism adaptation has been studied since at least the 1970s, for example in a 1979 paper by Schor, and more recently by a research group led by Alvarez and Scheiman.

Talasan and colleagues, 2016: 12 adults with normal binocular vision did 12 hours of repeated step and ramp vergence practice, and 11 did not. After practice, vergence movements started sooner, settled sooner and were more accurate, with larger changes than in the untrained group. The near point of convergence and phoria did not change.
Horwood and colleagues, 2014: 156 young adults without symptoms were randomized to two weeks of different eye exercises, placebo or no treatment. Convergence exercises increased near vergence responses. Encouraging a no-treatment group to try harder also increased responses, and the authors wrote that true treatment effects were small.
Alvarez and colleagues, 2017: in 49 healthy adults aged 20 to 70, the ability to adapt vergence speed did not depend on age, while the amount of phoria adaptation fell with age.

Where Optics Trainer fits

Optics Trainer is a set of game-based vision and brain training apps for iPhone, iPad, Android, web browsers and Meta Quest. Its eye teaming games use red-blue glasses on a phone, tablet or computer, and the separation is built in on Meta Quest. There are three, and each also comes in Convergence and Divergence versions, which raise base-out or base-in demand:

These games keep the core of clinic vergence tasks: two pictures, one for each eye, with a demand that changes while you keep them single. They change the setting: a screen instead of prisms or polarized slides, swipes and taps instead of spoken answers, 60-second rounds, and no clinician adjusting the steps. They were not tested in any study described here. The Convergence and Divergence versions of Odd One Out and Front or Back show a result in the app; that is a practice result, not a clinical measurement of vergence ranges. Optics Trainer is not a treatment or diagnosis and is not FDA cleared. Optics Tracker, on our clinic site, is our measurement product. Optics Trainer is not a substitute for professional diagnosis or prescribed care. Consult your eye care professional for guidance about your specific condition.

The phone and tablet apps start with a 7-day free trial, and a free web account includes 3 plays a day. After that, mobile and web access is $14.99 a month or $149.99 a year, and VR access is $19.99 a month or $199 a year after a 7-day free trial.

Odd One Out: four pictures appear, and one sits at a different depth from the others. You swipe toward it. Three right answers in a row raise the demand, and two misses in a row lower it. It is modeled on depth judgments made while vergence demand steps up and down.
Front or Back: you swipe to show whether a picture sits in front of or behind a ring, with the same stepping demand. It is modeled on the same kind of depth judgment.
Motor Fusion: a picture pair slowly separates, and you tap when it splits in two; then a new picture starts. It is modeled on prism-bar or vectogram range practice, as practice only. Nothing is scored right or wrong.

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Frequently asked questions

What are vergence exercises?

They are exercises that practice turning the eyes in (convergence) or out (divergence) while keeping one single image. Clinicians use prisms, vectograms, computer programs and tools like the Brock string, and raise the demand in small steps.

What is fusional vergence?

Fusional vergence is the eye movement that keeps both eyes aimed at the same target, using the small difference between the two eyes' images. Your fusional vergence range is how far your eyes can turn in or out before the target doubles.

What are jump vergence exercises?

They ask you to switch quickly between two vergence demands, for example with flip prisms or by looking between near and far targets. A related clinic test, vergence facility, counts how many switches you can make in a minute.

What are prism vergence exercises?

You look through prisms that make your eyes turn in (base-out) or out (base-in) to keep a target single. A clinician raises the prism strength in steps, often with a prism bar or flip prisms.

Can vergence exercises help intermittent exotropia?

A 2021 Cochrane review included no trials of exercises. Since then, a 40-child trial in 2024 and a 177-child trial of home virtual reality therapy in 2026 reported better control scores than observation; the larger trial's authors called the change modest.

Can adults improve their vergence?

In trials of adults with convergence insufficiency, office therapy improved the near point and fusional vergence more than placebo, though symptoms improved in both groups. Studies of healthy adults found faster, more accurate vergence after practice.

Are there vergence games or apps?

Yes. Clinics use computer orthoptics programs, and Optics Trainer has eye teaming games with convergence and divergence levels. Optics Trainer was not tested in these studies and does not make clinical measurements of vergence.

Sources

Related guides

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Odd One Out, Front or Back and Motor Fusion come in Convergence and Divergence versions modeled on clinic vergence tasks, on phone, tablet, web and Meta Quest. The phone and tablet apps start with a 7-day free trial.

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