For most of us vision is the primary sense, providing the fundamental features of the world and our perception of space and objects. The other senses complete the picture suggested by vision and solidify our experience of the world and ourselves, but vision remains primary. In order to “see”, the eye and the brain need to work together and a sequence of biological processes and learning mechanisms are required to keep a consistent visual perception of the world.
How does seeing work and why is it affected by many conditions that have nothing to do with the eye? In a nutshell, light bouncing off an object is intercepted by our eyes. Or eyes contain biological lenses specialized to bend and converge the light onto the back of the eye, where the retina receives it. The retina is actually a part of the brain, containing the same type of cells, called neurons. From here on, the light frequencies are coded, as information about our surroundings enters the realm of the brain and continues to be translated, filtered, integrated, enhanced or reduced, and overall aligned with our cognition. We have two eyes for binocular (depth) vision, each eye forming its own image on the retina, yet we see a single image wherever we focus. This convergence of perception is due to both the ability of our eyes to track together towards objects, as well as the brain’s ability to create a single perception.
Ultimately whatever we perceive is to a large extent the result of brain processes, and when it comes to vision, we can definitely say that it is mostly “in our head”. All this becomes clear with trauma, especially when the brain circuits that process visual stimuli are impaired. Neurological vision impairment occurs when the eye is intact, yet vision information is not processed accurately by the brain. In this case, only treating the brain is effective for rehabilitation.
A brain injury – may it be developmental, due to an accident, or medical trauma from chemotherapy – can lead to a decreased ability to organize and make sense of visual information along with poor focusing or depth perception and difficulties with balance and posture. Blurred vision, double vision, difficulty with eye movements, loss of visual midline, sensitivity to light, or motion sensitivity (including getting dizzy while scrolling on a computer or losing your place while reading) are some of the most frequent complaints. To make matters worse, people try to compensate for these issues, resulting in a dysfunctional posture or eye movements, further deepening the issue. These spatial visual processing dysfunctions are often diagnosed as Post Trauma Vision Syndrome (PTVS).
Why do we feel dizzy and lose balance as a result of trauma? The vision circuits in the brain processing the position of objects in space are intimately integrated with the ones dedicated to balance and orientation in space, and also with pathways processing the movement of our body (e.g., with information from the joints). If either the balance or visual brain areas are damaged by disease, aging, or head injury, people will often experience difficulty with balance and movement as well as an abnormal perception of space. It can be difficult performing even routine daily tasks in environments with visual stimulation such as a grocery store, school, or work.
The good news is that alleviating trauma-related vision problems is possible based on a property called neuroplasticity, meaning that the brain is able to rewire itself and form new circuits. This property is the strongest during childhood, but still available at any age. Have you watched a baby learn to walk? Or how they learn to focus on an object? We take balance and vision for granted but both are learned skills, acquired through repetition and effort, resulting in a shaping of the very biology of the brain. Similarly, after brain trauma with vision impairment, the rehabilitation must include a relearning of vision and balance skills. This can be supported by many therapeutic approaches such as physical therapy, neuro-visual training, and neurofeedback, to name only a few. With qEEG-based neurofeedback, for example, the faulty brain circuits underlying the vision issues are rewired, session after session. Visual rehabilitation is relearning how to see. As new connections are formed, visual and cognitive exercises can further strengthen the newly formed links, towards restored vision.
The healing process can be challenging and tedious but it does not have to be frustrating given the right attitude. The process of rehabilitation offers a chance to slow down and learn to see the world anew, to develop new skills and change cognitive patterns. In letting go of old expectations and relearning to “see”, some find a new sense of appreciation for the world around them as well as the world “within”.
For more information contact:
Monica Metea, PhD
ReWire Neuroscience, LLC
Tel: 508.720.5679
admin@rewireneurosci.com
https://www.rewireneurosci.com/
