Nothing ‘Puzzling’ About It; ‘Vision’ More Than Just Eyesight
Jigsaw Pieces Prompt Reflection on Critical Role of Retinal Processing
What makes my new jigsaw puzzle from the Netherlands especially challenging is that the picture on the box cover will not be the ultimate depiction of the assembled puzzle. Instead, the puzzle is intended to show “what happens next” after something unknown occurs, which means, of course, I cannot simply rely on the box cover for visual cues as I pick through 1,000 puzzle pieces.
Scanning through the puzzle pile on the table, looking for edge pieces, I begin thinking about all the visual skills put into play to accomplish the task of putting together a puzzle. Constructing the puzzle border requires glancing and head movement side to side, while discriminating among puzzle-piece shapes and sizes, differentiating and comparing colors, determining – visually – how one piece might fit with the other and then using eye-hand coordination to put like pieces together. At this point, I realize how the entirety of my effort – the combination of sight, hearing and movement working in synchronization — represents such a great example of the role and critical importance of retinal processing in enabling us to understand and interact with the world around us and the need to update the standard 20/20 eye testing in today’s society.
The typical person thinks of vision as simply eyesight, but it is much more than that. In fact, as we discussed Patrick Quaid’s research, only about six percent of surrounding space comes from conscious attention on specific objects. Most environmental signals passing through our retinas emanate from peripheral space – the space all around us at a subconscious level of awareness.
We use central eyesight for stationary objects (like letters on an eye chart) but not for “seeing” targets that are moving. Having a general awareness of our environment is highly dependent on peripheral eyesight. Modern, fast-paced society abounds in moving targets – from signs and lights whizzing past us in traffic to ever-changing GPS navigation screens and words rolling in and out of sight on scrolling web pages. We use peripheral and central eyesight in tandem to scan and shift our gaze from place to place, such as when sifting through puzzle pieces. We use visual systems for assessing shape, size, color, contour, design, etc. and also for memory, planning, visualization and perception skills.
In other words, “vision” is both external and internal. It allows us – externally – to judge puzzle-piece shapes and – internally — to decide how these shapes must come together to create a whole. And, in the case of the “what happens next” puzzle, visualization allows predictions of future relationships. My puzzle shows a dog, cat, mouse, ducks and fish, along with the people. Except for the mouse eyeing some cheese, the other animals are barely moving. The likelihood is that one starts a chain reaction and probably knocks over the fish swimming in a fish bowl perched on a pedestal. The final design will not be the Norman Rockwell-like family portrait shown on the box.
The retina is made of brain tissue and sends signals to more than simply an eyesight center. Retinal signals combine (partially beneath a conscious level of awareness) with other sensory signals – from hearing, smell, taste and touch. Further brain processing synthesizes the information and reacts and responds depending on internal sensory signals. If brain circuitry is out of sync because it has been disrupted by injury or disease, or it is under-developed, people can become confused about their surrounding environment and exhibit inappropriate reactions and responses or experience difficulties in learning. When eyes and ears are not coordinated, people have to continuously monitor attention, and that effort becomes exhausting,
Did you ever consider the various visual skills children must employ to learn in school? Their challenges throughout the day are much like those involved in solving – and resolving — a multi-piece puzzle. Yet, most standard testing only checks the clarity of central eyesight, along with general eye health and some eye movement, but not necessarily how quickly and accurately a child shifts gaze from book to board and back to paper – a skill needed to copy information from a board. Some children labelled as learning-disabled are not learning-disabled at all. They have the capability – and capacity — to learn, but simply require intervention to help further develop and coordinate sensory systems (such as eyes and ears) in order to be successful.
As I have said so frequently before, the current eye evaluation process was developed in 1862 when much of the nation remained unsettled, overland travel was by horseback or horse-drawn wagons, and prairies and mountains dominated individuals’ peripheral sight. This 150-year-old testing system addresses central eyesight by having the patient consciously look at non-moving targets across a darkened room, but ignores peripheral retinal processing, which comprises an overwhelming percentage of a person’s visual awareness.
Today’s optometrists have many advanced tools to address deficits or imbalances in both central and peripheral eyesight. By using their knowledge to alter the way light disperses across the retina and readjust a patient’s visual balance and eye-ear connections, optometrists can positively affect patients’ external eyesight as well as their internal processing.
Let’s leave 20/20 testing where it belongs – in the 20th century. Now, back to the fascinating Dutch puzzle!
Deborah Zelinsky, O.D.
Founder, Executive Research Director
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Mind-Eye Featured in the News Media
Newspapers and television stations throughout the country have been reporting on the work of the Mind-Eye Institute. Read the articles below to learn more about what the Mind-Eye Institute is doing to pioneer change in how optometric evaluations are performed in the 21st Century.