By Deborah Zelinsky, O.D., Executive Research Director at The Mind-Eye Institute
Healthy brains are able to interpret and respond to the environment at many different levels almost instantaneously. So, it is not surprising that patients who have sustained a traumatic head injury or concussion, which oftentimes damages or scrambles brain circuitry, may exhibit information-processing (neurocognitive) deficits affecting their ability to interact in appropriate ways with people, activities, and events in the world around them.
Experts call the problem “brain fog”: an obscuring or shrouding of one’s thoughts; lack of clear thinking, focus, and concentration; confusion; memory issues; decreased reaction time; and difficulties comprehending – or remembering – what has just been learned, read, or been heard during social conversation. The Mind-Eye Institute sees patients who often complain of brain fog. One patient recently described her brain fog in this way:
“I was unable to do simple, everyday activities. I could no longer cook because my brain was unable to signal my hand to turn off the stove when my sense of smell indicated that food was burning. In the supermarket, I was overwhelmed with sounds, lights, smells, and the need to make decisions. I could no longer do calculations or keep track of time or use the computer. I had problems spelling words, writing words in cursive, and reading. I would read a paragraph from a book and forget what I just read.”
Another patient explained her brain fog as “Nothing making sense to me any longer. I would think, ‘Oh, I should do the laundry,’ but that is as far as I would take it. I never thought to gather up the clothes and get them cleaned. I would walk into a room and go completely blank: ‘Who am I; where am I?’ Then I would look at my feet and jog my memory, ‘Oh, yes, I am me, and I am standing in the bathroom.’”
Simply put, a brain injury interferes with visual processing, namely the simultaneous ability of the brain to take in external sensory signals (from eyesight, hearing, smell, taste, and touch) at all levels – unconscious, subconscious, conscious, meld them with one’s internal sensory signals, and then process the information. When retinal processing is dysfunctional and foggy, so is one’s understanding of the surrounding environment. Correct understanding is what is necessary for organizing, planning, and making decisions.
In a recent blog on my website, I related how a near accident involving a ridesharing van serves as a perfect example of levels of brain function. I was with a party of four about to embark on a relatively short ride in a ridesharing vehicle. Two of our group were already seated, one was waiting behind me, and I was literally stepping into the van when the driver started to pull away. My immediate action was to let out a primal scream and grab the door tighter – simply hold on as best I could. It was an unconscious, instantaneous, reflexive response for survival. Sensory processing then kicked in at a subconscious level as I became more aware of my environment of seeing and feeling the van moving. Finally, when my perception – and understanding — of the incident rose to consciousness, I was able to start yelling to the driver, “Stop,” which he did.
Because my visual processing and senses are intact, all these levels of perception – from reflex to awareness of the environment to consciousness – occurred nearly instantaneously, allowing me to react and appropriately respond to what was happening in my world. As the renowned cognitive neuroscientist A.R. Luria pointed out in his many publications, the healthy brain functions using multiple signaling circuits at various speeds. Of course, the differences in speed can be calculated in milliseconds or even nanoseconds.
Research has demonstrated the retina is a piece of brain tissue which is part of our body’s central nervous system. It not only sends the brain environmental signals through eyesight at a conscious level, but also from luminance (external light) that disperses across the retina at an unconscious level. Concurrently, the retina receives feedback signals from the body through informational pathways in the brain. This continuing process of feeding forward signals to the brain from the environment and receiving feedback signals from various brain structures makes the retina a two-way portal for influencing and monitoring thought processes and body functions, including posture, movement, and, of course, motor reflexes, such as my tightly gripping the door of the moving vehicle and screaming.
Each of our eyes contains approximately 126 million light-sensitive receptors. Input from the receptors moves through a sophisticated filtering system, which compresses the information into about 1.2 million signals that exit each eyeball. These signals travel across and radiate from the optic nerve through the many pathways inside the brain. In fact, the retina connects with many systems other than eyesight, including structures in the brain’s cortex, cerebellum, and limbic system, as well as midbrain and brainstem. All these structures affect the body’s reactions and responses, including activity in such systems as endocrine, respiratory, circulatory, circadian, digestive, and musculoskeletal.
With the retina having such an important impact on so many systems at different levels, any disruption in the retinal processing cycle due to head injury can cause a cascade of debilitating symptoms, including brain fog. Retinal processing is one portion of visual processing. Patients with retinal-processing deficits usually lack some degree of synchronization between their perception and target location. They often have difficulty visualizing auditory space, having difficulty determining where and from which direction sound emanates.
The Mind-Eye Institute applies new science discoveries to test patients’ retinal processing capabilities on many levels. Careful analysis results in a prescription of individualized activities and, most notably, “brain” glasses or Brainwear™, designed for comfort. With highly customized “brain” glasses, we are able to vary the amount, intensity, and angle of light passing through the retina and, in so doing, resynchronize a patient’s senses, particularly eyesight and hearing, as well as help the brain build new informational pathways.
Peripheral visual skills, which are required in today’s modern society with its mobile phone screens, movie and video-game special effects, highly-trafficked streets, and constant scanning of rolling information on computer displays and GPS systems, are becoming more important to assess. Properly functioning peripheral eyesight is necessary for normal visual processing to occur. Mind-Eye testing emphasizes peripheral visual skills, internal visualization, and linkage between auditory space perception and visual space perception. Glasses prescribed for these purposes tend to be comfortable, and patients have fewer symptoms while on the long road to recuperation.
Speaking of roads, just as the sun eventually burns away the early morning fog enshrouding a highway, so light passing through specially prescribed lenses can burn away the fog of an injured brain. Thanks to advanced scientific practices, the Mind-Eye Institute is striving to return quality life to many patients with traumatic brain injuries.
Let there be light!
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. www.mindeye.com/tbiquiz