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Vision Therapy
What is VT?
Eye Exercises
Vision Tests

For Parents
Stereo Vision
Lazy Eye
Cross- Eyed
Vision & LDs

Vision impairments which affect at least
15 out of 100 people . . . yet,
frequently go unrecognized and/or untreated.

Vision Therapy is the Effective Treatment!
Vision therapy is an effective, medically proven treatment for binocular vision impairments, such as double vision, lazy eye, crossed eyes, amblyopia, strabismus, esotropia, exotropia, esophoria, exophoria, hypertropia, hyperopia, loss of stereoscopic vision, poor depth perception, convergency insufficiency, poor tracking, etc.
Some vision therapy providers also offer vision therapy programs as a means of reducing or eliminating the need for prescription lenses in cases of myopia (nearsightedness), hyperopia (farsightedness), presbyopia (farsightedness due to aging), astigmatism, and more.
Vision therapy has also been very helpful in many cases of children and adults who have been previously diagnosed (or misdiagnosed) with learning disabilities or developmental delays such as add-adhd or attention deficit disorder, dyslexia, autism, and more.

Top Ten Questions About Vision Therapy
  1. What is a Binocular Vision Impairment?
    Lazy Eye (Amblyopia), Wandering Eye, Wall-eye, Crossed-eyes (Strabismus, Exotropia, Esotropia), Double Vision, Convergence Insufficiency

  2. Why Are Binocular Vision Impairments Often Ignored and Unrecognized?

  3. What is Vision Therapy?

  4. Where can I find Vision Therapy Providers?
    Receive a free referral immediately.

  5. Why is Vision Therapy Such a Well-kept Secret?

  6. Is This an Eye Problem or a Brain Problem?

  7. Early Detection of Vision Problems-- A Parent's Checklist

  8. What is The Stereo Vision Project?

  9. What is Stereo Vision?

  10. What is Depth Perception? Why Do We Need It?

PLEASE NOTE: The information contained herein is intended to be educational and is not intended in any way as a substitute for medical advice and care from qualified, licensed eye care providers - you are invited to visit the U.S. Directory of Vision Care Providers for a referral in your area.

What is The Stereo Vision Project?

The Stereo Vision Project was created to raise public awareness of stereo vision (stereoscopic vision) and binocular vision impairments, such as amblyopia ("lazy eye") and strabismus (wandering eye, wall-eyes, crossed-eyes esotropia, exotropia, hyperopia), convergence insufficiency, etc.

The Stereo Vision Project is committed to providing information about effective treatment for binocular vision impairments. Many individuals with these visual defects are not informed of all treatment options and are not gaining access to a treatment that offers a significant success rate: vision therapy or orthoptic therapy.

The Stereo Vision Project maintains contact with many people who were told by ophthalmologists or optometrists that their lack of binocular depth perception was permanent and untreatable. These people were told to learn to live without depth perception, but instead went on to develop normal binocular depth perception by undertaking supervised programs of "visual training" or "vision therapy." For this reason, the Stereo Vision Project strongly recommends that any person with a binocular vision problem consult an eye care professional who does offers vision therapy. Some eye care professionals may not inform you of this treatment option.

The Stereo Project also hears from many people with binocular vision defects who have had disappointing results with eye muscle surgery. Surgery on their eye muscles failed to restore binocular vision and, in many cases, did not even produce lasting cosmetic improvement (the eyes still didn't look "straight" or the wandering eye went astray once again). The Stereo Vision Project has reviewed studies on surgery which report success rates ranging from 30% to 60%. One study has shown only a 50% success rate as a result of surgical treatment for strabismus. In that study, success was defined as ANY long-lasting positive benefit. That is, the case was counted as a success if the patient gained ONLY a cosmetic benefit (the eye appeared more straight to others), but had no improvement in visual function. Ideally, more long-term controlled studies will be done to evaluate the success rates resulting from surgical treatment of strabismus.

The Stereo Vision Project hopes that all patients will be informed that one strabismus surgery often leads to another. Ask the surgeon if multiple surgeries may be recommended. To read more about eye muscle surgery, go to

This page aims to inform parents and patients of alternatives to surgery and further hopes that surgery will be called into question as the treatment of choice in many cases of strabismus.

What is Stereo Vision?

Stereo Vision is a byproduct of good binocular vision, so let's start with definitions of binocular and binocular vision.

BINOCULAR:Of or involving both eyes at once

BINOCULAR VISION:Vision wherein both eyes aim simultaneously at the same visual target; vision wherein both eyes work together as a coordinated team -- equally and accurately.

O.K., now you're ready for . . .

STEREO VISION:(stereopsis or stereoscopic vision) vision wherein two separate images from two eyes are successfully combined into one image in the brain

Stereo vision is an aspect of "normal" healthy vision. Here's how it works. First, both eyes must be accurately aimed at the same target (that's binocular vision, but it's not yet stereo vision!) Then, because the two eyes are located in different positions, each takes in a unique view from its own perspective. The two separate images are sent on to the brain for processing. When the two images arrive simultaneously in the back of the brain they are united into one picture. The combined picture appears three-dimensional (3-D) because it has the added depth dimension. That's stereo vision. Stereo vision gives you depth perception. For an illustrated definition, see the Stereo Vision page.

What is Depth Perception and Why Do We Need It?

DEPTH PERCEPTION:an important aspect of normal, healthy vision; a result of good stereo vision; the ability to visually perceive depth and three dimensional space; the ability to visually judge relative distances between objects; a perceptual skill that aids accurate movement in three-dimensional space.

You need depth perception because . . .
According to the web site of the American Academy of Ophthalmology, August, 1996: "many occupations are not open to people who have good vision in one eye only [that means no stereo vision, no binocular depth perception]"

Here are a few examples of occupations that depend heavily on stereo vision:

  1. Baseball player
    binocular vision
  2. Waitress
  3. Driver
    depth perception
  4. Architect
  5. Surgeon
    eye care
  6. Dentist

The loss of binocular depth perception robs a person of more than just the possibility of being a professional baseball player or dentist The Stereo Vision Project asserts that the lack of binocular vision is a serious visual disability that deserves more attention. Loss of binocular vision decreases quality of life as well as life choices. Parents and patients need to be informed about early detection of these conditions as well as the full range of treatment options.

Here are a few examples of general actions that depend heavily on depth perception:

  1. Throwing, catching or hitting a ball
  2. Driving and parking a car
  3. Planning/building a three-dimensional object
  4. Threading a needle and sewing
  5. Reaching out to shake another person's hand
  6. Pouring into a container
  7. Stepping off a curb or step

What is a Binocular Vision Impairment?

Lazy Eye (Amblyopia), Wandering Eye, Wall-eye, Crossed-eyes (Strabismus, Exotropia, Esotropia), Double Vision, Convergence Insufficiency

A binocular vision impairment is any visual condition that results in partial or total loss of stereoscopic vision and binocular depth perception.

These visual disabilities are more common than you may think. Just one type of binocular impairment, amblyopia ("lazy eye"), affects approximately 3% of the population. At least 12% of the population has some type of problem with binocular vision. Plenty of people are seeing the world with only one eye. They are monocular (one-eyed), not binocular (two-eyed). [Remember the monocles that people used to wear in the nineteenth century?]

Many monocular people can be rehabilitated with the help of vision therapy. They can become binocular and gain depth perception! The Stereo Vision Project seeks to call attention to binocular vision impairments and to educate parents and the public about treatment options.

Some binocular disabilities are easily noticed by others, such as conditions where both eyes obviously don't aim in the same direction. These conditions are commonly referred to with terms like "cross-eyed", "wall-eye" or "wandering eye". Some of medical terms for these misalignments of the eye are strabismus, esotropia, exotropia.

PLEASE NOTE: Some binocular disabilities are not detected because the turning or straying of the eye(s) is not obvious or consistent. Some eye turns are intermittent (they come and go) and are not easily noticed by the untrained observer. That's why early detection is so important.

Why Are Binocular Disabilities Often Ignored and Unrecognized?

Possible answers:
  1. It's a health problem that doesn't kill (unless we were to attribute some accidents to it).

  2. People who have never known normal depth perception don't know what they're missing.

  3. Some binocular disabilities are not easily detected by untrained observers because the turning or straying of the eye(s) is not obvious or consistent. Some eye turns come and go and are not so easily noticed. That's why early comprehensive eye examinations are so important for children.

What is Vision Therapy?

VISION THERAPY: (also known as vision training or visual training, behavioral optometry): A form of supervised therapy aimed at improving visual skills, such as eye teaming, depth perception, tracking and vision-body coordination (more typically called "hand-eye" coordination).

Vision therapy is a rehabilitative therapy. It can be described as physical therapy for the brain and eyes. Through a progressive series of therapeutic procedures, patients who lack stereo vision or other adequate visual skills can trained to control their eye muscles and how to see effectively with both eyes. Vision therapy is remarkably successful in rehabilitating all types of binocular vision impairments including amblyopia (lazy eye), strabismus (crossed-eyes), esotropia, exotropia, esophoria, exophoria, hypertropia, hyperphoria, as well as other binocular conditions. Vision therapy (or orthoptics) is a completely medically accepted and proven practice when applied to binocular vision conditions, such as lazy eye and crossed eyes..

Vision therapy is also used to treat many other visual conditions such as:

  • nearsightedness (myopia)
  • farsightedness (hyperopia)
    aging eyes
  • farsightedness due to aging (presbyopia)
    hand-eye coordination, poor coordination, uncoordinated
  • avoidance of reading due to poor eye coordination
    slow reader, problems with reading
  • astigmatism
  • accommodation or accommodative problems
  • eye strain and headaches associated with poor vision

Vision therapy is inexpensive compared to surgical treatments and is usually covered by major medical insurance policies.

To learn more about vision therapy, go to

Vision therapy is NOT the Bates Method. The Bates Method was invented by W.H. Bates, an ophthalmologist who wrote Perfect Sight Without Glasses (New York, 1920). Vision therapy involves a medically supervised program of therapeutic procedures. The techniques and technologies of vision therapy were reviewed and developed throughout the twentieth by doctors of optometry. Research and review continues in the 21st century. In some cases, regulated medical devices, such as lenses and prisms, are used.

NO GUARANTEE OR WARRANTY IS STATED OR IMPLIED: While Vision Therapy has been extremely effective for many individuals, no guarantee as to the effectiveness in any specific case is made by The Stereo Vision Project. Patient outcomes can vary widely from individual to individual, and as such, no warranty is stated or implied.

Why Is Vision Therapy a Well-kept Secret?

  1. The media rarely brings in the cameras. We've all seen dramatic camera footage of people struggling in physical therapy, being taught to walk again after a stroke or other injury. Watching a child doing vision therapy would not make such a dramatic picture--most of the action is happening inside the child's brain and can't be picked up by the eye of the camera.

  2. Vision therapy is practiced by optometrists, so -- depending on the doctor you consult -- you or your family may not be informed of this treatment option. Keep in mind that ophthalmologists are specialists and that their practices concentrate on the use of drugs and surgery to treat eye disease and trauma. Many factors add up to the likelihood that you may not easily stumble upon an eye doctor who offers vision therapy. To learn more about this subject, visit

Is This an Eye Problem or a Brain Problem?

It's both! The visual system includes the brain as well as the eyes. The eyes are actual physical extensions of the brain. Binocular vision disabilities often involve problems with how the brain processes the visual information coming in through the eyes. Even so, many people with eye turns (strabismus) are frequently offered eye muscle surgery only. Surgery might make the eyes appear straight to others, but it often does very little to change the way the brain controls the eyes or processes visual information. Often the patient's eyes return to their misaligned position(s) following surgery. To learn more about eye muscle surgeries, visit

Consider the tremendous advances that have been made in the last forty years in the fields of neuroscience, occupational therapy, physical therapy and sensory integration. In these professions, scientists and health care professionals understand that the human brain is capable of tremendous change, recovery and development. Today, patients who suffer strokes or other traumatic injuries to the brain and nervous system receive extensive rehabilitation. Therapeutic procedures (exercises) teach patients how to coordinate movement--how to breathe, speak, and/or walk. In his speech at the 1996 Democratic convention, Christopher Reeve referred to the signifcant progress that has already been made in rehabilitative therapies. Vision is such a vital sense. Why isn't the mainstream visual health care field more progressive? Why don't more vision care professionals take advantage of the marvelous gains that have been and are still being made in neuroscience and other rehabilitative health care fields? Clinical and research developments in vision therapy have been closely allied with developments in neuroscience.

Vision therapy (or orthoptic therapy) is a very effective type of physical therapy for the brain and the eyes. People with binocular disabilities can often learn to see normally by undergoing this type of rehabilitative therapy.

Words more frequently misspelled are pediatric ophthalmologists and pediatric ophthalmology? For example, people spell them: as pediatric opthamology, pediatric opthamologists, opthalmologists, opthalmologist, etc.. Makes it hard to find stuff, doesn't?

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Magic Eye How to See 3D copyright © 1995; Out-of-Print
by Magic Eye, Inc. and Rachel Cooper.
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