Sensory: Smell, Taste, Vision, Hearing



I sustained a severe head injury from a fall several years ago. I currently have vision problems, such as occasional double vision and difficulty focusing on one object. I have seen an optometrist who recommended eye glasses; however, I think I need to see a specialist, perhaps an ophthalmologist with brain injury expertise. Is there such a specialist, and if so, what can I expect from this type of doctor? If not, whom should I see?


Residual visual problems (sequelae) persisting beyond six months post-head injury are considered recalcitrant (not self-remitting). Problems of double vision (diplopia) and difficulty with focusing (accommodation) are secondary to brain stem (mid-brain) trauma resulting in binocular decompensation. The term decompensation relates to a disturbance of the previously learned innervational patterns that have been established over the developmental lifetime of the patient. The traumatic derangement of the very sensitive balance of innervation patterns controlling the six yoked muscle pairs controlling ocular alignment (12 individual muscles) and the sensory-motor response system of accommodation results in a loss of synchronization and coordination of fine motor control, resulting in the variable visual episodes that result in visual stress. When these decompensations prevail for months, compensatory adaptations develop as a survival response. These compensatory adaptations, while enabling the patient to survive, are not adequate to the demands of a highly technological society requiring efficient binocular (clear single) vision.

The recognized professional domain with the expertise to deal with the diagnosis and rehabilitation of such problems is referred to as the rehabilitative optometrist. This emerging specialized field of optometry is identified as neuro-rehabilitative optometry. The professional organization providing the leadership, communication, training and certification in this domain is known as NORA, Neuro-Optometric Rehabilitation Association, International. NORA is a multi-disciplinary organization which has evolved to integrate those health care professionals and disciplines involved in visual-cognitive rehabilitation secondary to TBI. The members of NORA come from many professional disciplines, having established charter, education, and certification programs, a journal, and annual conference.

Patients seeking answers to the questions regarding visual dysfunction secondary to head injury should contact NORA at the following web site and communication address:

P.O. Box 1408
Guilford, CT 06437
(949) 250-0176

NORA can provide you with the name of a specialist in your geographical area and the status of that individual’s certification.

Neuro-optometric examination of TBI patients involves the exploration of the many integrated subsystems that comprise the visual process. Such an examination will usually require more than one visit and may involve two to four hours of examination and analysis. The first step in a comprehensive neuro-optometric examination is the establishment of the integrity of each eyeball as a receptive organ representing the first step in the visual process. Next, a refractive analysis is performed (similar to a routine eye glasses or contact lens examination). After establishing the state of integrity of the structures of the eyeball and its refractive status, then a 21-point probe battery is performed to evaluate the oculo and sensory motor subsystems of the visual process. The result of that probing process directs the examining doctor to further in-depth, sustained, performance-based visual studies to evaluate the integrity of information processing of the visual system and visual perceptual status.

It must be appreciated by patient and all health care professionals dealing with the head-injured patient that it is rarely the eyeball that is the problem. The problem exists in the brain stem, the infra and supra nuclear processing centers that integrate the visual information accessed by the two receptor organs (eyeballs) to a final binocular perception Efficient binocular input facilitates cerebral processing and association with previously acquired (learned) experience, information, and new input information, producing a final meaningful and accurate cognitive perception. This in-depth examination and analysis will result in a diagnostic statement/report describing the domains of dysfunction (diagnosis), a clinical estimate of potential for rehabilitation and recovery (prognosis), and a plan recommendation for rehabilitation.


  1. Langlois JA, Rutland-Brown W, Wald MW. The epidemiology and impact of traumatic brain injury. J Head Trauma Rehabil. 2006;21(5):375–78. doi: 10.1097/00001199-200609000-00001.
  2. Faul M, Xu L, Wald MM, Coronado VG. Traumatic Brain Injury in the United States: Emergency Department Visits, Hospitalizations and Deaths 2002–2006. Atlanta (GA): Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; 2010
  3. Report to Congress on Mild Traumatic Brain Injury in the United States: Steps to Prevent a Serious Public Health Problem. Atlanta (GA): Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; 2003. “TBI: Get the Facts” Centers for Disease Control and Prevention. Accessed 2/2018
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  7. Gianutsos, R. "The Use of Personal Computers for the Rehabilitation of Visual Perception." Presented to the American Academy of Optometry. St. Louis, MO. December 10, 1984.
  8. Perlin, R.R., Ramsey, G., Blouin, M., and Gianutsos, R.R. "Rehabilitative Optometric Services for Survivors of Brain Injury." Presented to the American Academy of Optometry. Atlanta, GA. December 13, 1985.
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  10. Santa Clara Valley Medical Center Vision Rehabilitation Therapy, research grant awarded by The National Institute of Disability and Rehabilitation, awarded 1987 and renewed in 1991.

*For those professionals interested in further research, NORA maintains a bibliography in excess of 200 citations relating to visual dysfunction secondary to traumatic brain injury and optometric rehabilitation.


Since the accident, I can’t see as well as I used to. My visual field is limited. In other words, sometimes I can only see a narrow focal point; my peripheral vision is limited. I’m wondering if my eyeball is damaged or if this problem is due to brain damage. Should I see a neurologist or an eye doctor?


The patient’s experience of limited or loss of visual field is a common occurrence in head injury. This phenomena may be a mild field compression that is the result of stress secondary to binocular decompensation (refer to the related FAQ on vision problems) or it may be as serious as neurological damage of the retina, optic nerve, optic visual pathway (from eyeball to brain ), or damage within the visual cortex of the brain .

In mild closed head injury, this phenomena is statistically most frequently a field compression that is secondary to stress of decompensation. This type of field restriction is generally resolved as the components of binocular decompensation are rehabilitated. The diagnostic probes to determine the nature of the visual field restriction, neglect or scotomatous (retinal zone) loss. The in-depth and hierarchical diagnosis of this problem is the domain of the rehabilitative (neuro) optometrists. If retinal damage is identified, the rehabilitative optometrist will refer that patient to a vitreo-retino specialist. If damage to the brain is identified, this is usually diagnosed by the neurologist prior to the patient being examined by the rehabilitative neuro-optometrist. The MRI is usually the definitive diagnostic tool for delineating brain lesion location and extent. The MRI, however, is supported by functional/behavioral diagnostic analysis.

In summary, visual field constriction or loss rarely exists in the absence of the other common dysfunctions of vision subsequent to head injury. When in doubt, the patient should see the rehabilitative (neuro) optometrist who will provide the triage to determine the appropriate management of the condition.


What are some vision problems that people with traumatic brain injuries may experience? How are such problems diagnosed and treated?


Ten years ago, I started treating people with traumatic brain injury. At that time, the typical treatment that these patients were receiving involved prescribing lenses, if necessary, to enable the patient to see clearly. If double vision were reported, the person would be patched. Many of these patients were visually frustrated trying to read, write and drive. In short, visually guided activities presented difficulties and frustrations they had not experienced prior to their injury.

Sight is the ability to see clearly; vision is the ability to derive meaning from what is seen. As a developmental Optometrist, my standard examination evaluates many aspects of human visual performance. In addition to a standard eye exam, I do an in-depth evaluation of areas such as tracking (eye movements), focusing, depth perception and binocular vision.

Typical symptoms resulting from traumatic head injury include:

 1. Intermittent double vision and/or blurred vision when attempting sustained visual activities (i.e., reading or driving). Many individuals experience constant double vision.

 2. Headaches, fatigue and loss of concentration while reading.

 3. Loss of depth perception.

 4. Loss of visual field.

 5. Difficulty with eye-hand and eye-foot coordination.

 6. Lack of ability to visualize; frustration doing simple puzzles.

Due to the nature of the rehabilitation process, impairments of the visual system are generally diagnosed last. Often the patient has been discharged from the hospital and the rehabilitation services available in that setting. As they attempt to resume "normal activities" in less structured surroundings, they may realize that their visual system is limiting their progress.

Typically a patient with traumatic brain injury has a significant problem in one or more areas mentioned above. The use of lenses is one of the first options available to the patient. In addition to a prescription for clarity at distance, patients can benefit from lenses used for reading. Double vision can be reduced significantly, often eliminated, by the use of specific prism lenses. Appropriate lenses have been used successfully to alter gait, movement patterns and balance. Very recently, a new lens has been developed that can allow the patient to detect motion earlier in those areas of a visual field where sight has been lost.

The patient's decreased efficiency of ocular movements and focusing abilities, binocular vision skills, and visual thinking schemes can be improved through a program of Visual Training/Therapy. Many developmental Optometrists offer this therapy which provides a unique opportunity to improve these critical areas of functioning. Treatment involves a series of activities that provide the experiences that facilitate relearning the visual processes once taken for granted by the patient. The activities do not involve "muscle building;" they instead result in changes in the thinking, perception and processing of information. It is vital that this treatment be done in an office setting and that the optometrist monitor the therapy. The treatment requires specific equipment, experience and expertise. I feel it is crucial that every patient who has experienced a traumatic brain injury be examined by a developmental Optometrist. For many, treatment can provide a pathway to improved performance in their daily activities.  


I have experienced significant balance problems since sustaining a severe brain injury over a year ago. I cannot tell if the balance problems are tied to my vision impairment or some other problem. Is it possible to regain my equilibrium, and if so, how?


Balance is maintained using a combination of systems in the body including vision and ankle, hip and trunk movements. A deficit in any of these areas has the potential to cause balance disturbances. The good news is that most balance problems can be improved with exercise and practice. Here are a few common problems which cause balance disturbances and simple ways to correct them. However, if your balance problem interferes with your ability to accomplish tasks during your day, you may want to consult your physician and ask to be evaluated by a physical therapist.

Vision Disturbances

We rely heavily on our vision to inform us of the type of surface we are walking on and use it to prep -- re for changes we may need to make to accommodate our environment. Without the use of vision, it becomes more difficult to detect changes in the angle of the surface we are walking on or to prepare for sudden changes in the surface we are walking on. If your head injury altered your vision you may need to find a way to compensate for your loss. A new pair of glasses may be needed, or you may need to use a cane to help you sense changes in the ground that you cannot see clearly. A good use of this strategy would be for someone who has difficulty going up or down stairs due to the inability to determine the height or depth of the step. 

Ankle Problems

Our feet are the first part of our body to hit the ground. Deficits in our ankles cause our entire balance system to be off. If you cannot sense the ground beneath your feet, they can't properly tell the rest of your body what to do. If your ankle motion is restricted, then your feet don't have the motion needed to keep the rest of your leg and body over the area you are standing on. Performing simple Achilles' tendon or heel cord stretching can help improve motion. Practicing standing on one foot, for as long as possible, can also improve ankle strength.

The Achilles' tendon stretch is performed by standing and facing a wall. Place both hands on the wall and one foot flat on the floor behind the other. Keep your back knee straight and your front knee slightly bent. Lean forward until you feel a stretch in the back of your calf in the back leg. Hold this position for 10 seconds then stand up straight. Repeat 5 times, then switch your feet so the one that was just stretched is now in front. 

Hip and Trunk Weakness

The muscles of our thighs, stomach and back all work to keep our bodies centered over our legs. If these muscles have become weak, they are less effective in helping us regain our balance and keep our bodies over our feet. Exercise can greatly improve this type of problem but the program must be tailor-made to each patient. If you suspect this type of problem, consult your doctor for a referral to a physical therapist.

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