By Mark Rosner, M.D. and Debby Feinberg, O.D.
Vision Specialists of Michigan

Thank you to our guest authors Dr. Mark Rosner, Director of Education and Research at the NeuroVisual Medicine Institute and Dr. Debby Feinberg Director of Vision Specialist of Michigan.

Despite the current treatment approaches to patients with persistent post-concussive symptoms, some individuals remain quite symptomatic.1 Advancements are being made, including one that can bring significant additional relief to this population.

It now appears that in many mild traumatic brain injury (TBI) patients having symptoms lasting greater than three months, a subtle vision misalignment is being found.2 Traditional vision evaluations do not routinely find this subtle vision misalignment (known as vertical heterophoria or VH) as the standard tests are not sensitive enough to identify it. A specialized testing method was successfully developed by Dr. Debby Feinberg resulting in a new approach to treatment of patients with persistent post concussive symptoms as well as the creation of a new optometric specialty called NeuroVisual Medicine.


Robin suffered a TBI as the result of a significant motor vehicle accident and was treated by an optometrist trained in NeuroVisual Medicine. Here is her story:

In July 2015, Robin suffered a traumatic brain injury due to a car accident. She had seen several specialists to find relief from her symptoms including a neurologist, neurosurgeon, and several physical therapists. None of these specialists were able to give her the relief she so desperately needed. The TBI caused her severe headaches and neck pain as well as crippling anxiety. As someone who was typically very bubbly, happy, and outgoing, this was very difficult for her to endure.

Robin’s symptoms became an obstacle to performing her job as a nurse. She used to be someone who could remember patient names, dates, and medications with no problem. Now she was a person struggling to remember the most basic things, and that made her job difficult. She had a hard time driving to patients’ homes and found herself taking long routes to avoid traffic because it was now hard for her to judge distances between herself and other cars. She also found herself having headaches that were crippling. Robin felt like she was a completely different person. She had constant fears that her symptoms would cause her to lose her job.

After her initial exam and using the aligning lenses, everything changed for the better. Robin felt instant relief from her symptoms. She felt confident again. Things just felt better. She is now able to drive without anxiety or fear. The biggest impact has been on her career. Robin can now read patient medical records without confusion or losing her place. She isn’t nervous or anxious about being ineffective at work. Treatments she had tried previously offered minimal to no relief, but the glasses with aligning lenses changed her life for the better.


Humans use their two eyes together as a team in order to see. This allows for depth perception as well as the ability to see a three-dimensional image. Under normal circumstances, the two eyes work smoothly together to look directly at a target or to follow the target as it moves. This is known as binocular vision. However, there are many circumstances where the two eyes do not work together smoothly, and this is known as Binocular Vision Dysfunction or BVD. Causes of BVD can include problems with the eye aiming muscles, with the nerves that direct those muscles to move, or with the brain itself (by sending faulty aligning signals to the eye aiming muscles).

Some forms of BVD can cause large eye misalignments, leading the person to see double. Some forms known as heterophorias only cause very small misalignments, and the person avoids double vision by struggling significantly all day long to maintain alignment. The most common form of BVD we see is Vertical Heterophoria, or VH.


Traditionally, the medical community associates only a few symptoms with VH, the most prominent being double vision. In our experience, only about one-third of those who suffer from VH have double vision. The most common and bothersome symptoms they experience are not usually thought of as having a visual cause. These include:

  • Headache
  • Anxiety
  • Nausea
  • Difficulty with balance
  • Light sensitivity
  • Anxiety while driving
  • Difficulty with reflection/glare
  • Dizziness, light-headedness
  • Neck pain
  • Difficulty with gait stability
  • Reading and learning difficulties
  • Motion sickness
  • Overwhelmed in large spaces or crowds
  • Difficulty with depth perception


The two most common ways one can acquire VH is through suffering a TBI or being born with it (congenital). The exact location of the damage for those suffering a TBI is not clear. In congenital cases, facial asymmetry in the vertical dimension (i.e. where one eye is somewhat higher than the other) plays a role as does aging. While we may be able to compensate for the misalignment when we are younger, it becomes more difficult to do so as we age, which is why the most common age of onset for those with the congenital form is around 40 years old. Please note that while not as common, children as young as 8 months and adults in their 90s can develop VH.


It might be difficult to believe that a vision misalignment could be the cause of so much discomfort, and it is for this reason we have developed a “simulator” that allows most people to feel some of the symptoms that VH patients feel. The picture below has two sets of eyes and lips that are vertically separated, causing the viewer to struggle to obtain a single vertical image (Figure 1). VH patients are experiencing the exact same struggle—trying to maintain a single vertical image. We are fortunate in that we can look away from the picture and have our symptoms resolve. Unfortunately, VH patients cannot do that—this is how they can feel all day, every day.

Figure 1. Vertical Heterophoria (VH) simulator
Looking at this picture for just 15 seconds will cause many people to experience the same symptoms that patients with VH have (nausea, anxiety, eye pain/headache, dizziness), and for the same reason they are both struggling to see a single image and to avoid seeing double vision.


Since the symptoms of VH are not currently recognized as belonging together (i.e.-syndromic), it is common to have these symptoms individually evaluated by the specialist for that particular symptom – the patient is sent to the neurologist for assessment of the headache, the psychiatrist for assessment of the anxiety, the otolaryngologist (ENT) for assessment of the dizziness, etc. As a result, patients are misdiagnosed with a whole host of conditions, and treatments and medications prescribed frequently are not effective in bringing relief because the real cause of the symptoms—VH with vision misalignment—is not being identified and treated. The mistaken diagnoses include: TBI with persistent post-concussive symptoms

  • Migraine associated vertigo; vertiginous migraine
  • Migraine headache; atypical migraine headache
  • Muscle tension headache
  • Chronic daily headache
  • Torticollis
  • Sinusitis
  • Benign paroxysmal postural vertigo (BPPV)
  • Meniere’s Disease (typical and atypical)
  • Vestibular neuronitis
  • Labyrinthitis
  • Persistent Postural Perceptual Dizziness (PPPD)
  • Psychogenic dizziness
  • Chronic subjective dizziness
  • Generalized anxiety disorders (GAD)
  • Panic attacks
  • Agoraphobia
  • ADD / ADHD
  • Dyslexia
  • Malingering


Since the traditional tests for VH have been found to not be sensitive enough to find the small heterophorias that are causing symptoms in these patients, a new approach was needed. NeuroVisual Medicine Specialists are trained to perform not only the traditional tests but to look for clues about the patient’s visual alignment in the alignment of their bodies (i.e., what is their posture? how straight do they walk down a hallway?). Using these tests and observations as a baseline, a technique called Prism Challenge is then used. This technique involves adding very small amounts of prism (i.e., micro-prism) to a test frame that contains the patient’s baseline prescription. The patient is then “challenged” with ever increasing amounts of prism until two important goals are reached: vision is maximally clarified, and symptoms are minimized as much as possible or sometimes even eliminated. The average patient will experience an immediate 30-50 percent reduction of symptoms during the initial evaluation.

Also noticeable immediately is an improvement in fine motor control, as it is very dependent upon stable vision. In the sets of pictures at the right (Figures 2 and 3), one was drawn before and the other just a few minutes after micro-prism lenses were applied.

While this approach is not yet widely known, it has been utilized since 1995 in over 10,000 patients (of which about 40 percent have TBI), resulting in an average 80 percent reduction of symptoms once the treatment process is completed (approximately two months).3  

Figures 2 & 3. Drawings created before and after prism lenses (same day).


While this treatment can successfully reduce many bothersome symptoms, it can only do so in those who actually suffer from VH. To aid in identification of those individuals, two screening tools have been developed that allow both the doctor and the patient to know that a NeuroVisual examination would be worthwhile.

The first tool is the Binocular Vision Dysfunction Questionnaire or BVDQ,4 a 25-item survey that asks the patients about the frequency with which they are experiencing certain VH symptoms. A questionnaire can be found at

Scoring is based upon frequency of symptoms: Always = 3 points, Frequently = 2 points, Occasionally = 1 point, and Never = 0 points. A score of 15 or more points indicates a high likelihood that a binocular vision condition is present and that a NeuroVisual evaluation would be beneficial.

The second screening tool is the 5 Minute Cover Test.5 In this test the patient is instructed to cover one eye for five minutes to determine if they experience significant symptom reduction. By covering one eye, the patient is preventing themselves from using binocular vision. Reduction of symptoms of at least 30 percent with the eye covered, with an immediate return of symptoms when the eye is uncovered, is very indicative of a binocular vision issue, and a NeuroVisual examination is warranted.

There is a specific technique to follow to perform the test correctly and an instructional video can be found at


The average patient has been symptomatic for 10 years and has spent considerable time and effort to find relief from their symptoms. It is not surprising that when people become aware of this treatment approach (either through word of mouth or internet searches) they are willing to travel great distances to receive this life altering care. After hundreds of patients had traveled from all across the US, Canada and even Europe, Australia and Asia, it became clear that NeuroVisual Specialists should be in easy reach of the patients who require their services. For this reason, the NeuroVisual Medicine Institute began its training program of teaching other optometrists how to perform this work. Since 2013 over 25 optometrists from across the US and Australia have become NeuroVisual Specialists. However, given how common this condition is (affecting at least 10-20 percent of the general population and at least 50 percent of the TBI population), it is clear many more NeuroVisual Specialists will be needed.


It is now possible to identify and treat very small vision misalignments that can be the root cause of many serious and debilitating symptoms experienced by those with persistent TBI symptoms. The availability of optometrists trained in NeuroVisual Medicine is growing, making care more accessible than ever. Simple screening tools exist that can identify to the doctor and the potential patient exactly who might benefit from a NeuroVisual examination. Given the large reduction of symptoms experienced by the average patient (80 percent), this treatment is very frequently life changing.


1. Kraus J, Schaffer K, Ayers K, Stenehjem J, Shen H, Afifi AA. Physical complaints, medical service use, and social and employment changes following mild traumatic brain injury: A 6-month longitudinal study. J Head Trauma Rehabil 2005;20:239-256.
2. Kapoor N, Ciuffreda KJ. Vision disturbances following traumatic brain injury. Current Treatment Options in Neurology 2002;4:271–280
3. Doble, J. E., Feinberg, D. L., Rosner, M. S., & Rosner, A. J. (2010). Identification of binocular vision dysfunction (vertical heterophoria) in traumatic brain injury patients and effects of individualized prismatic spectacle lenses in the treatment of postconcussive symptoms: a retrospective analysis. PM&R, 2(4), 244-253.
4. “BVD Questionnaire: Vision Specialists of Michigan: Bloomfield Hills, MI.” Vision Specialists of Michigan,
5. Vision Specialists of Michigan. “5 Minute Cover Test for Binocular Vision Dysfunction.” YouTube, 27 Jan. 2017, watch?v=auLrPQqf-AM&