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Posted on 08-08-2013
Most people don’t give their eyes or their vision a second thought. These are the lucky ones…probably. An unknown number of people who don’t’ give their vision a second thought would be significantly better off if they did. Most eye doctors are content with providing lenses that help people see more clearly. Not that there’s anything wrong with that. But the eye exams performed by these doctors are very likely to ignore many problems that are directly linked to the visual process. Many people have symptoms like headaches, dry eyes, eye fatigue or discomfort, getting drowsy when reading, etc because their visual systems are not working the way they should. Similarly, children with learning difficulties, behavior problems, attention problems, poor coordination and developmental delays (particularly those on the autism spectrum) often have undiagnosed visual conditions that are intimately involved in the problems they are having.
“Vision is the brain’s way of touching.” Maurice Merleau-Ponty
The most basic visual skill is the ability to aim the eyes precisely, either to follow a moving target or to look quickly and accurately from one object to another. It is also important to be able to keep the eyes pointed at a particular object for some desired or needed length of time. This probably sounds pretty easy. It should be. You’re probably certain you do this all the time. This is not always the case. We are not always pointing our eyes exactly where we think we are. And while this may not be a big deal much of the time, it might be a bigger deal than you realize. And there’s no way to know exactly how this might be impacting your daily performance. It’s difficult to imagine how things could work differently because you have no way to make a comparison.
Everything we do takes more effort and yields reduced results when our eyes are not automatically and consistently aiming where we want, when we want. Most eye doctors do not consider this an issue unless there is some drastic reduction in the ability to aim the eyes because of a damage eye muscle, which is extremely rare. And yet, it is those of us with the subtle difficulties that often have the greatest reduction in performance and comfort as we perpetually struggle to adjust for this seemingly tiny error. And so I asked the question…(The following was presented at the Kraskin Invitational Skeffington Symposium on Vision, January 18, 2003 and includes some minor revisions. Do not be surprised if you find yourself chuckling, laughing, or perhaps groaning periodically as this was my intent. I have chosen not to add emoticons so you’re on your own.)
Don’t look at me that way. Why are you looking at me with one eye while your other eye seems to be more interested in something or someone else?
Are you looking at me? You could be intending to look at me. You might be trying to look at me. You might even be absolutely certain that you are in fact looking at me. To those of you who are successfully looking at me – I apologize for any inconvenience or discomfort this may cause.
The problem is – How do you know that you really are looking precisely at me? I’m not trying to imply or suggest that I may be an illusion – you can wish that all you want, but it’s unlikely. Neither am I suggesting that you are an illusion. My point is that it’s not as easy as it looks to know precisely where your eyes are pointing or to consistently aim them exactly where you intend. While this may appear to be an issue so simplistic it’s not worth looking at, I am suggesting that it is instead one of the most critical aspects of the visual process as well as one of the most overlooked – or perhaps more accurately – under-looked.
The ability to quickly and accurately point our eyes is fundamental to all of our visually guided activities, from walking and running to reading and writing to throwing and catching to driving and parking. Everything we do can be made easier or harder depending on the quality of our ability to point our eyes precisely where we intend at each moment.
Other than peripheral awareness, perhaps the most fundamental aspect of the visual process is the ability to point the eyes at a desired object. Once you have looked at a few things of course, you needn’t look at anything else for the visual process to be active. There may be some truth to the old saying, “if you’ve seen one, you’ve seen ‘em all.” Though I would probably adjust it to, “if you’ve seen once, you’re seeing always” in that once the visual process has been turned on you can’t really turn it off. (All of this of course assumes not being totally blind.) The visual process is still at work even with the eyes closed as we continue to revisit or generate imagery. However, between your first looking experience and your last breath you’ve got a lot of looking to do so you may as well make the most of your time by looking at as much as possible. Unfortunately, this is where things can start to fall apart, and they often do. Difficulty with precise pointing of the eyes is at the root of most visual inefficiency. Focusing, depth perception, eye/hand coordination and timing cannot be at their best if the two eyes aren’t precisely pointing at the same thing at the same time.
Looking is a more complex action than you might think. Let me define looking (for the purposes of this post) as aiming the mind and the two eyes (if you’ve got ‘em) precisely at a distinct target. Each eye must be accurately pointing in its own right. While it is possible to look solely with the mind while the eyes are otherwise occupied or vice versa, I’d like to overlook that idea for the time being. Assuming there is a specific object of interest, there are many possible scenarios when we look at that specific object:
1) One eye may be aimed precisely at the object while the other eye is aimed (purposely or otherwise) somewhere else. This can result in
a) each eye producing a clear image of the object (double vision) or
b) one eye providing a clear image of the object while the other eye produces a not-so-clear image of the same object if the eyes have unequal acuity (double vision) or
c) one eye providing a clear image of the object while information from the other eye is actively ignored by the brain (single vision with suppression) or
d) one not-so-clear image of the object (single vision with suppression)
2) Both eyes are aimed in the general vicinity of the object. This can result in
a) one clear-ish image of the object with a good sense of where it is in space or
b) one clear-ish image of the object with a poor sense of where it is in space or
c) two clear-ish images of the object with a poor sense of where they are in space
3) Both eyes are aimed precisely at the object. This is likely to result in
a) One clear image accurately located in space
People don’t always report seeing double for a variety of reasons that we don’t need to go into at this time. People hardly ever realize that the brain is ignoring the input from one eye (suppression). The bottom line is that many visual disturbances escape notice by most people. These same visual disturbances also go unnoticed during a routine eye exam. It usually requires a behavioral optometrist to expose these hidden weaknesses, though it is not uncommon for occupational therapists to recognize the presence of some of these problems because OTs recognize the importance of the visual process and the importance of behavioral optometry and vision therapy.
The visual process should and usually is mostly an unconscious process. As I said earlier most of us rarely think about our eyes or how we are using them. How do you know exactly where you’re looking? Do you have proof? Can you tell when you’re off by a hair…or a foot? An evaluation by a behavioral optometrist can begin to uncover the answers to these questions and vision therapy can actually improve the accuracy and flexibility of our ability to point our eyes, but that’s for later.
There is some play in the system, but the more accurate we are and the less effort we exert the better the system runs. As I stated earlier, the accurate and effortless aiming of the two eyes is the foundation of every visual action. The lack of accurate and effortless aiming of the eyes can be the start of any of a number of functional visual deficits. Most of these are amenable to therapeutic lenses and/or vision therapy. The vast majority of these conditions are often misdiagnosed, undiagnosed or are simply ignored by both patient and doctor, causing untold difficulty with learning, earning a living and/or recreational pursuits such as sports.
All the adaptations we make in response to reduced visual efficiency can be helpful in the short-term and may even help us function over the course of many years. Ultimately these adaptations are like building a house atop a swamp. It may look beautiful from the outside and it may hold up well for some length of time, but serious structural failings are all but inevitable. And at some point it is very likely that symptoms will emerge from all the extra work the visual system must do to manage all the adaptations.
Just as the journey of a thousand miles starts with a single step, so the process of visual difficulty begins with a wayward glance. Well, maybe not just one. A common scenario is some initial glitch in the problem solving process where perception of the location of the object of regard does not quite (or at all) match the object’s actual location. This results in the activation of corrective and/or supportive maneuvers by all visual subsystems and often by the head and neck if not the entire body. The system attempts to find the most efficient, least demanding approach to get the job done. Long-term consequences are likely to result if such a response occurs repeatedly – there are consequences for every action, some expected some not, some desirable, some less so. If the mismatches do not in essence become “structured in” the adaptive process must continue its search for a consistently satisfying replacement strategy or ignore the problem. This usually means avoiding the kinds of activities that depend on the function in question. Prime examples of consistent inefficiency pointing the eyes include children who avoid reading and sports.
Either of these alternatives – the constant adjustments and adaptations or the avoidance approach – may actually be preferable to settling on a less than optimal substitute. This assumes appropriate help is found in a timely manner. Repeated or chronic compensations for continuous mismatches often cause the mismatch/response complex to become permanently structured in – functionally and physically; this usually makes the vision therapy process a bit more challenging though no less important. Of course all of these – the inaccurate looking, the search for compensating strategies, consequent mismatches and adaptations – usually occur without the slightest knowledge of the participant. It is rare for there to be any conscious awareness that any of this is going on.
It is not particularly complicated to evaluate a person’s ability to look. The typical brief screening done by most eye doctors to determine the integrity of the eye muscles is not sufficient. It’s too easy for someone to look capable for the ten seconds it takes to do this. A more in-depth evaluation of eye movements is necessary to determine that an expected level of performance is easily and consistently available for an appropriate period of time. A little time must be devoted to observing the accuracy of the looking process. Only behavioral optometrists tend to evaluate eye movement in any kind of depth, looking for quality and not just quantity. This is critical in assessing the present condition of the visual system as well as understanding the particulars of the vision therapy program necessary to improve visual development, performance and comfort – all of which begins with pointing the eyes.
The portion of the vision therapy program to improve looking skills is similarly simple and similarly time-consuming to the evaluation of those skills. There are no good short cuts. It does require some extra time with direct observation and dialogue to provide feedback. While there are many ways to provoke better accuracy in pointing the eyes, the best are the simplest and most direct. There are more and more computer programs emerging that claim to be equally effective if not more so. There is no substitute for a trained practitioner/observer working directly with a patient.
It’s true that many people seem to do just fine without finely tuned visual systems. It’s also true that almost anyone can benefit from the improvement in performance that typically results from a good vision therapy program. My experience both as a behavioral optometrist, a vision therapy provider and a vision therapy patient make me certain that even those who do just fine without finely tuned visual systems would have increased comfort, greater efficiency and all-around improved performance if they improved their visual abilities with vision therapy. So when I say, “don’t look at me that way” I only mean it out of caring.
Next time: Breaking News – The Story of Nick and his Super Gobstopping Headache
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