Peer Reviewed

Vergence Dysfunction

Article Summary

Vergence dysfunction occurs when a person has difficulty coordinating movement of the two eyes to maintain single binocular vision. Vergence eye movements are crucial for aligning the eyes accurately on a target at different depths, allowing for depth perception.  Vergence dysfunction can cause challenges in properly coordinating the muscles that control the inward and outward movement of the eyes, which can lead to eye strain, double vision, headaches, blurred vision, difficulty maintaining focus, and general discomfort.

 

What is vergence dysfunction?

Vergence dysfunction refers to a condition where there are difficulties or abnormalities in the coordinated movement of the eyes to maintain single binocular vision. Binocular vision involves the simultaneous use of both eyes to perceive a single, three-dimensional image of the environment. Vergence eye movements are crucial for aligning the eyes accurately on a target at different depths, allowing for depth perception and stereopsis (perception of depth and three-dimensionality).

In individuals with vergence dysfunction, there may be challenges in properly coordinating the muscles that control the inward (convergence) and outward (divergence) movement of the eyes. This can lead to symptoms such as eye strain, double vision (diplopia), headaches, blurred vision, difficulty maintaining focus, and general discomfort, especially during tasks that require sustained near vision, such as reading, writing, or using digital screens.

Vergence dysfunction can result from various factors, including sensory issues such as an imbalance in the visual input from each eye, motor control problems affecting the eye muscles, neurological conditions, or developmental issues. Diagnosis typically involves a comprehensive eye examination, including tests to assess binocular vision and eye movement coordination. Treatment approaches may include a type of vision therapy, corrective lenses, prismatic glasses, and other interventions aimed at improving binocular vision function and alleviating symptoms.

Does vergence dysfunction cause dizziness?

Vergence dysfunction can sometimes be associated with symptoms of dizziness or vertigo, although IT IS RARELY a direct cause. Dizziness in the context of vergence dysfunction may occur due to the close relationship between the visual and vestibular systems.

The vestibular system, located in the inner ear, helps maintain balance and spatial orientation. It works in coordination with the visual system and proprioception (sensory information from muscles and joints) to provide a sense of equilibrium. When there is a discrepancy or inconsistency between visual input and vestibular signals, such as in cases of vergence dysfunction where there may be difficulties in binocular coordination, it can lead to sensory conflicts. These conflicts can sometimes manifest as sensations of dizziness or vertigo.

Additionally, individuals with vergence dysfunction may experience visual symptoms such as blurred vision, double vision, or eye strain, which can indirectly contribute to feelings of discomfort or dizziness, However, it’s essential to note that dizziness can have various causes, and vergence dysfunction ONLY RARELY LEADS to dizziness AS THE MAJOR SYMPTOM. Nevertheless, all patients with chronic vestibular symptoms would benefit from a careful ophthalmologic evaluation by a medical doctor with neuro-ophthalmologic specialty training. If someone experiences persistent or severe dizziness, it’s important for them to consult with a vestibular healthcare professional for proper evaluation and diagnosis.  

How do you treat vergence dysfunction?

The treatment of vergence dysfunction typically involves a combination of therapeutic approaches aimed at improving binocular vision and reducing symptoms. Treatment strategies may vary depending on the specific symptoms, underlying causes, and severity of the condition. Here are some common approaches:

  • Vision Therapy: Vision therapy is a structured program of visual activities usually implemented by an optometrist or vision therapist. These specific eye exercises are designed to improve eye coordination, focusing ability, and binocular vision skills. Vision therapy may include activities such as convergence exercises, divergence exercises, near-far focusing exercises, tracking exercises, and stereoscopic training. 
  • Prism Lenses: Prism lenses can be prescribed to help alleviate symptoms of vergence dysfunction, especially double vision, by modifying the way light enters the eyes. Prism lenses can help reduce the effort required to align the eyes properly, especially during tasks that require sustained near vision. Note that lenses do not correct vergence dysfunction but can be a coping tool.
  • Corrective Lenses: Prescription glasses or contact lenses may be prescribed to correct refractive errors such as nearsightedness, farsightedness, or astigmatism, which can contribute to vergence dysfunction.
  • Vision Training Devices: Various computer-based or digital vision training devices may be used to supplement traditional vision therapy exercises. These devices can provide interactive and engaging activities to improve eye coordination and visual skills. There is little scientific evidence, however, that they can alleviate symptoms in patients whose major problem is dizziness.
  • Home Exercises: Patients may be instructed to perform specific eye exercises or activities at home as part of their treatment regimen. These exercises are typically tailored to the individual’s needs and may complement in-office vision therapy sessions.
  • Environmental Modifications: Adjusting the visual environment, such as reducing glare, optimizing lighting conditions, and minimizing visual distractions, can help alleviate symptoms of vergence dysfunction and improve visual comfort.
  • Collaboration with Other Healthcare Providers: In some cases, collaboration with other healthcare professionals such as neurologists, ophthalmologists, or physical therapists may be necessary, especially if there are underlying neurological, vestibular, or musculoskeletal issues contributing to the condition.

It’s important for individuals with vergence dysfunction to undergo a comprehensive evaluation by a qualified eye care professional to determine the most appropriate treatment plan for their specific needs. Treatment outcomes can vary, and regular follow-up appointments may be needed to monitor progress and adjust the treatment regimen as necessary.

Also note that THERE IS as yet NO SCIENTIFIC EVIDENCE THAT demonstrates the efficacy of treatment for vergence dysfunction in people with vestibular disorders. A multidisciplinary approach is therefore important to ensure that underlying vestibular issues are being addressed.

What type of healthcare professional should you see if you suspect you may have problems with vergence dysfunction?

If you suspect you may have problems with vergence dysfunction, it is advisable to seek evaluation and treatment from an eye care professional, specifically an optometrist or an ophthalmologist. Both optometrists and ophthalmologists are trained to diagnose and manage various eye conditions, including binocular vision disorders like vergence dysfunction.

Optometrists are healthcare professionals who specialize in primary eye care, including vision testing, prescribing glasses and contact lenses, and diagnosing and managing eye conditions. They are skilled in evaluating binocular vision function and can perform comprehensive eye examinations to assess vergence and eye movement coordination. An optometrist with board certification in vision development and vision therapy is well equipped to diagnose and manage vergence dysfunction.  

Ophthalmologists are medical doctors who specialize in the diagnosis, treatment, and management of eye diseases and disorders. They have advanced training in both medical and surgical interventions for eye conditions. While ophthalmologists primarily focus on medical and surgical treatments, they can also diagnose and manage binocular vision disorders such as vergence dysfunction. A board-certified ophthalmologist with a subspecialty in pediatrics, strabismus, or neuro-ophthalmology is best equipped to diagnose and manage vergence dysfunction.  

Both optometrists and ophthalmologists may use specialized tests and equipment to assess binocular vision function, including tests to evaluate convergence, divergence, eye movements, and depth perception. Based on the evaluation findings, they can develop an appropriate treatment plan tailored to your specific needs, which may include vision therapy, prescription glasses or contact lenses, prism lenses, or other interventions to improve binocular vision and alleviate symptoms of vergence dysfunction. Consider residency training, fellowship, and board certification when searching for an eye care professional who can diagnose and manage vergence dysfunction. 

By The Vestibular Disorders Association, reviewed by Dr. Habib Rizk, MD and Dr. Joel Goebel, MD