Brain Injury/Concussion/Neuro-Optometric Rehabilitation

Post-Trauma Vision Syndrome (PTVS)

PTVS is a collection of visual signs and symptoms that are related to dysfunctions with the dorsal or ambient visual pathway. This pathway is responsible for organizing ourselves in space for balance and movement. The dorsal/ambient visual pathway tells us “where” we are in relation to our environment or "how" to get to them vs “what” things are. It receives information primarily from our peripheral vision and “grounds” us to be able to focus on details in our central vision. Much of this processing occurs at a sub-conscious level and coordinates with other systems related to balance and/or head positioning such as the inner ear and the neck. PTVS can interfere with eye movements causing difficulty in accurately pointing, tracking, and focusing the eyes during reading or other visually demanding tasks. It has been found that special prisms, binasal occlusion, and/or neuro-optometric rehabilitation are useful tools in restoring balance in this system.


Symptoms of PTVS include but are not limited to:

  • Eyestrain, especially while reading or using the computer

  • Double vision

  • Blurred vision

  • Low blink rate/dry eye or watering eyes

  • Depth-perception issues

  • Sensitivity to light (photophobia)

  • Difficulty with eye-tracking

  • Headaches

  • Dizziness

  • Difficulty reading

  • Poor balance

  • Difficulty navigating through crowded or tight spaces

  • Visual memory problems

  • Difficulty concentrating

  • Disorientation

  • Driving difficulties


Abnormal Egocentric Localization: Abnormal Egocentric Localization (AEL) results from a dysfunction in the dorsal (ambient) visual pathway. It is caused by distortions of the visual-spatial processing system, which results in a shift in the perceived visual midline (or what appears straight ahead). This can cause one to lean to one side, forward or backward and/or feel dizzy and off balance. It can also make one feel like there is reduced depth perception or feel spatially disorientated. Patients often complain that something doesn't seem right with their vision but have a hard time describing why it is hard. AEL can contribute to headaches, nausea and visual motion sensitivity. Severe AEL is often associated with strokes involving the parietal lobe but less severe forms can exist after other types of milder head injuries or neurological insults. Interventions may include specially designed prisms prescribed into glasses and/or binasal occlusion to reduce the disconnect between visual perception and the physical world; thereby, improving function. Neuro-optometric Rehabilitation may also be needed with an emphasis on visual-spatial orientation.

Treatment Options for Patients with Brain Injury/Concussion

  1. Therapeutic and Functional Prescription Lenses: While most glasses are prescribed for eyesight alone, a therapeutic lens is designed to help improve visual function. Therapeutic lenses can reduce visual stress on the eyes, improve spatial and peripheral vision organization, enhance depth perception, and help the person process the visual information more effectively and efficiently.

  2. Binasal Occlusion (BNO): Binasal Occlusion is a method of partially occluding or covering, part of the vision in the nasal area (area close to the nose). This is usually done in a “V” shape to allow the eyes to converge when looking up close. The amount of occlusion is determined through special testing done by a Neuro-Behavioral Optometrist who has specialized training. Binasal occlusion has two main purposes: to reduce the confusion of overlapping of images that occurs in the central portion of the visual system where the images from the two eyes overlap allowing for better peripheral fusion/binocular vision and/or to help stabilize and organize the ambient (peripheral) visual processing system with the focal (central) visual processing system. Binasal occlusion can be helpful when treating binocular vision dysfunctions in both children and adults that result in double vision or strabismus (an eye turn). It is also a tool used to reduce Post-Trauma Vision Syndrome, Visual Motion Sensitivity Syndrome, Abnormal Egocentric Localization and other visual-vestibular conditions.

  3. Neuro-optometric Rehabilitation: Neuro-optometric rehabilitation is a specialized form of vision therapy designed to address and treat visual and perceptual problems resulting from neurological conditions. These conditions can include traumatic brain injury (TBI), stroke, multiple sclerosis, cerebral palsy, and other neurological disorders that affect the visual system. The goal of neuro-optometric rehabilitation is to improve the patient's visual function, which can enhance their overall quality of life and ability to perform daily activities.


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