By Deborah Zelinsky, O.D.
“Our entire biological system, the brain and the earth itself, work on the same frequencies,” said Nikola Tesla, the late 1800s/early 1900s inventor and electrical and mechanical engineer. But traumatic brain injury (TBI) – even a mild concussion – may knock the central nervous system (CNS) off that frequency, resulting in abnormal perceptions and aberrant responses to the surrounding world.
That prompts the central question: How does one get the CNS back online after a TBI? Will head-injured patients ever be able to view the world once again through rose-colored glasses? Well, they may not always come with rose-colored filters, but highly individualized “brain” glasses may be exactly what a patient needs to return their CNS to “earth frequency.”
What is it about glasses, though?
To understand the answer, one must first realize how the retina serves as a critical component of the central nervous system, which includes the brain and spinal cord. The retina acts as a primary portal for information to the brain. Environmental signals in the form of light pass through the retina and convert into electrical signals that propagate through neurons and interact with critical brain structures.
Head injuries can distort retinal processing, namely the brain’s ability (partially beneath a conscious level of awareness) to filter signals passing through the retina and then forward the filtered version for further brain processing. Through this “further processing,” the brain combines retinal signals with other sensory signals (from hearing, smell, taste, and touch externally, as well as from vestibular and proprioceptor input and many types of interoceptors), synthesizes the information, and then enables a person to react and respond in ways dependent on the individual’s many internal sensory signals.
Retinal signals interact not just with the visual cortex (for eyesight), but affect other, significant regions of the brain as well, like the hypothalamus, the cerebellum, and the brainstem. This implies stimulation of the retina can impact regulation of basic physical, physiological, and even psychological processes, including motor control, posture, emotions, and perception. Based on individual experiences and sensory integration, perception serves a key factor in decision-making. After a TBI disrupts sensory integration, the trickle-down effect skews perception, ultimately affecting decision making.
As a piece of brain tissue, the retina is much more than a sensory system for seeing. It provides information to integrate an individual’s senses, including eye-ear coordination based on a perceptual mapping of the environment. Brain injury and neurological disorders like Alzheimer’s disease disrupt this sensory synchronization and sensory mapping of space. When central and peripheral eyesight fail to interact appropriately and eyes and ears fall out of synchronization, patients often become confused about their environment, have a narrowed perception and awareness, exhibit inappropriate reactions and responses, and experience difficulties with cognitive skills including learning and memory.
Researchers writing in a 2017 edition of The American Journal of Pathology determined that 80 percent of combat veterans exposed to blasts developed long-term changes to their retinas, even without any discernible brain injuries. In this particular project, scientists considered how these retinal alterations led to “visual impairments” among studied veterans. But, because the retina does far more than signaling the brain’s visual cortex, one might assume a percentage of these same veterans also developed other symptoms related to impaired retinal processing – such as light and sound sensitivities, headaches, problems with memory and concentration, loss of emotional control, even behavioral abnormalities.
A more recent study, this one appearing in a November 2021 issue of Communications Biology, suggests the ways in which different regions of the CNS, most specifically those in the brain, interact with each other affects a person’s behavior and controls emotions. The investigators reported study participants with anxiety disorders visualized well-defined “safe spaces” as areas of fear and potential threat. Like head injury, anxiety disorders and other neurological problems can cause brain dysfunction and visual processing disorders.
The CNS constantly receives, sends, and interprets informational signals emanating internally from all parts of the body and arriving externally through the retina from the environment. These signals enable the CNS to make cognitive decisions on what we should do or how we should act at any given time. Those decisions are modified or governed in part by the “How Am I?” brain pathway. If we are awake, motivated, and energized, we will act much differently than when sleepy, fatigued, hungry, and, of course, injured.
Head trauma disrupts sensory signals. Such disruption causes a cascade of symptoms that can disrupt the “How Am I?” pathway, thereby making its victims chronically uncomfortable, impacting their decision-making, and perverting their responses to the world around them. Case in point: a report published in a November 2021 issue of the journal Science suggests the CNS processing of feedback signals from the body regulates emotions, including fear. If this body-brain interaction becomes muddled by injury, a person can be put into chronic fight-or-flight mode, experiencing panic attacks, anxiety disorder, or even post-traumatic stress disorder (PTSD). The new book Total War on PTSD, by Lieutenant Courtenay Nold, describes 46 non-pharmacological ways of addressing PTSD.
PTSD keeps a patient’s mind and body systems in a hypersensitized “fight-or-flight” mode. Common PTSD symptoms include changes in perception and cognition, which, in turn, cause abnormal reactions to the environment, and affect awareness and attention. A person with PTSD often suffers from spatial dysfunction and disorientation. Their visual world may constrict because peripheral sight becomes either hypersensitized or turned off. The patient might fail to pick up all surrounding environmental cues and expend more mental and physical energy to make “sense of everything,” become “wiped out,” and eventually find it easier to “tune out.”
This struggle to understand the environment can lead to depression, irritability, outbursts of anger, irrational behavior, and sleep problems, including nightmares. Biochemical changes also occur in response to disruptions in awareness. Stress chemicals reach higher levels, promoting a PTSD patient’s chronic state of survival.
But, back to the retina and eyeglasses – even if they are not rose-colored.
As a result of expanding knowledge about the retina and application of advanced optometric science, the Mind-Eye Institute achieved well documented, clinical successes in using eyeglasses – not just ordinary eyeglasses, but highly individualized brain glasses – to balance sensory signaling. That balance lessens the stress chemicals produced and often diminishes symptoms of TBI. By varying the amount, intensity, and angle of light passing through the retina, brain glasses help restore synchronization to TBI patients’ sensory systems; alter their awareness, attention to, and understanding of what happens around them; restore normalcy to patients’ visual processing skills; and bring a return of comfort and relief.
The importance of the retina has long been undervalued. Yet, the retina is often the key to returning patients to quality life. Patients sometimes refer to their brain glasses as “magic glasses.” But there is nothing magical about them.
Indeed, it’s simply science at work, or, as one of our patients coined it, the glasses are “mathemagical.”
Deborah Zelinsky, O.D., is a Chicago optometrist who founded the Mind-Eye Connection, now known as the Mind-Eye Institute. She is a clinician and brain researcher with a mission of building better brains by changing the concept of eye examinations into brain evaluations. For the past three decades, her research has been dedicated to interactions between the eyes and ears, bringing 21st-century research into optometry, thus bridging the gap between neuroscience and eye care.