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Convergence insufficiency is difficulty maintaining binocular vision at a near distance, which means your eyes have issues focusing together on things close up. (Learn More)
There is no specific known cause for convergence insufficiency; however, conditions that impact the brain and genetics may be factors. (Learn More)
To diagnose convergence insufficiency, your doctor will need to recognize the symptoms and perform specialized tests beyond a regular eye exam. (Learn More)
Treating convergency insufficiency relies on vision therapy and eye exercises that you learn from a professional and continue to practice at home. (Learn More) Many insurance companies and policies offer coverage for vision therapy. (Learn More)
Convergence Insufficiency Explained
Convergence is the way your eyes work together via binocular vision to focus on things that are up close. Convergence insufficiency is a breakdown of this ability. One or both eyes are not able to turn inward together; in fact, the eye or eyes often turn outward instead.
Convergence insufficiency is not caused by weak eye or face muscles. Instead, it involves neuromuscular ability, the muscle function that is controlled by nerves.
Symptoms of convergence insufficiency can include the following:
- Double or blurry vision
- Eye strain
- Squinting one eye
- Difficulties reading or viewing a computer or tablet screen
- Trouble concentrating
- Issues with motion sickness or vertigo
- Written words appearing to move
Symptoms will most often occur when you are trying to look or focus on something up close. About 2 to 13 percent of children and adults in the United States have convergence insufficiency. It can impact people of all ages, though it is most common in young adults.
Risk Factors for Convergence Insufficiency
Scientists and doctors are not clear on the exact cause of convergence insufficiency, but it does seem to run in families. It is a common side effect of a concussion or traumatic brain injury, but other causes are more difficult to pinpoint.
Potential risk factors for convergence insufficiency can include several conditions that affect the brain such as these:
- Alzheimer’s disease
- Parkinson’s disease
- Graves’ disease
- Myasthenia gravis
Long periods of computer use can be another risk factor for convergence insufficiency. You may be born with the condition, or it may develop over time.
Diagnosing Convergence Insufficiency
Convergence insufficiency is not detected on a routine eye exam. Especially in children, it can get missed or misdiagnosed.
It is important to talk to your doctor about all of your symptoms. They may run specialized tests and perform a comprehensive eye exam to diagnose the condition.
The eye doctor will look for and use certain measurements.
- Near point of focus: The doctor will use an object and bring it toward your nose to see at what point you start to have double vision. They will also determine the location of the closest point to the face that the eyes converge. If your near point of focus is further than 10 cm away from your nose, a deeper evaluation for convergence insufficiency is needed.
- Positive fusional vergence: The doctor uses a series of prisms and increases their magnitude while asking you to maintain your single vision for as long as you can. The normal convergence amplitude is 38 prism diopters for near vision. Someone with convergence insufficiency has convergence amplitudes of less than 15 to 20 prism diopters.
- Exodeviation: This is the point at which your eyes start to drift outward when you are trying to focus on something up close. Your exodeviation breaking point will be measured in both your standard position and reading position to test for convergence insufficiency.
- Accommodation: The doctor will check your ability to shift focus from far to near, as difficulty focusing on objects up close is a sign of convergence insufficiency.
The most effective treatment method for convergence insufficiency is in-office vision therapy with a trained professional, followed by practicing the exercises at home.
Vision therapy is a form of active treatment that requires training and ongoing eye exercises to retrain the eyes to work better together. While there are many at-home exercises, they are often ineffective without the help and oversight of a trained professional.
The best treatment for convergence insufficiency is orthoptic convergence exercise. Studies have shown these exercises to be effective in reducing symptoms. If untreated convergence insufficiency can lead to serious issues, including amblyopia (lazy eye), strabismus (eye turn), or visual suppression. This can cause the brain to stop using one eye, leading to a loss of binocular vision and impaired depth perception.
Exercises for Convergence Insufficiency
Common exercises used to treat convergence insufficiency include the following:
Pencil pushupThis is one of the front-line exercises for convergence insufficiency, Hold a pencil at arm’s length away from your nose. Slowly bring the pencil closer, keeping it in focus and stopping when you notice double vision. Try to focus and bring the object back into single vision, holding it there for 30 seconds. If you are unable to do this, draw it slowly back away from your nose until you can.This exercise needs to be done daily for at least 15 minutes. While it is convenient and can be done at home, it is less effective than in-office methods.
Prism exercisesA prism is placed on the wall at eye level. You will focus on it and keep it in single vision. Keep taking steps back or forward until it is out of focus. Prisms can also be used in glasses or as a single hand-held prism for near tasks, to stimulate the converge reflex.
Convergence cardsThese cards usually have dots or circles on them. You will hold a card up near the bridge of your nose and focus on the dot or circle that is at the furthest edge of the card, moving your eyes inward along the dots/circles until you can only see one line, or your vision becomes double.
Gradual convergence exercisesA red filter can be used to help with suppression of one eye. With this exercise, a red filter is held in front of one eye, and a light is held at arm’s length. When moving the light closer to the eye, the red or pink color from the filter will become white at the point of divergence and double vision.Try and hold the single vision at the closest point possible for at least 30 seconds.
StereogramsThese cards have two similar but separate images on them, separated by a horizontal axis. You will hold a pen in front of the card in the middle of the two images and focus on this. The goal is to cause a third image to appear in the center and be able to focus clearly on all three images.
Vergence facility exercisesThis exercise has you switching quickly between near and far targets to work on accommodation.
Computer-based convergence exercisesThis is a program used by eye care professionals. It uses random dot stereograms and jump convergence exercises that can progress with you as you move through vision therapy.
Treatment and exercises are dependent on the person. They work best when practiced both in the office with a trained eye care professional and also at home on your own in between sessions.
Insurance Coverage for Treatment
Convergence insufficiency is a medical condition that many insurance companies and policies will cover. Typically, treatment includes vision therapy, and insurance often covers this in the case of convergence insufficiency. Check with your individual provider and policy to determine your coverage specifics.
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Convergence Insufficiency Explained. (August 2019). Healthline.
Convergence Insufficiency. American Academy of Ophthalmology (AAO).
Convergence Insufficiency. American Optometric Association (AOA).
Convergence Insufficiency. (December 2014). University of Iowa Health Care Ophthalmology and Visual Sciences.
Convergency Insufficiency. (April 2020). Optometrists Network.