Convergence Insufficiency

 

Convergence Insufficiency (CI) is the most common interference with maintaining precise binocular alignment in which a person’s eyes cannot be seen to turn. It is one of a class of conditions which produce similar signs and symptoms. Each of these conditions are treated with lenses, prisms, and/or optometric vision therapy. To be visually comfortable and efficient, binocular alignment must be within a ½ degree angle. Eyes that slip in, out, up, or down from this precise alignment compromise visual input. The effects are most obvious in reading due to the complexities of the task and the requirement for sustained ocular motor precision and speed. Eyes jump and stop to look four times a second while reading, or about 250 times a minute. When eye alignment drifts even minutely during these jumps, the eyes must realign at each stop or the degraded visual input will interfere with perception.

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Because there is no obvious deviation of the eyes, these conditions are often overlooked. Problems are observed but it may not be realized that they are visual. Individuals, particularly children, may not report their visual disturbances because the disturbances are normal for them. A problem-focused history may bring them out. (See the Convergence Insufficiency Symptom Survey at the end of this blog.) Diagnosis of these conditions requires additional testing, beyond what is usually considered to be a comprehensive examination. Examinations which do not include this testing tend to add to the confusion when patients are told that there is nothing wrong with their eyes.

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Convergence insufficiency causes a person’s eyes to not triangulate accurately and automatically for reading, writing, and using electronics. The system may work for a limited time but not have the stamina to maintain comfort, attention, and accuracy.

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Convergence insufficiency rarely occurs in isolation. It is almost always associated with difficulty focusing and is often coexists with poor tracking. Like other neuromuscular coordination problems which lead to compensations, it is subject to fatigue. The problem is exacerbated by prolonged eyestrain. This occurs as the school year proceeds or after additional eyestrain at work over a period of weeks or months. Staring is particularly stressful. This happens to children when they must stare to decode words as they are reading. It also takes place in the early years of writing before making letters and words become automatic and children must stare at their pencil point as they are drawing letters.

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Avoidance is the most common sign in children. For adults who find avoidance impossible, eye fatigue, headaches, and sleepiness are most common. When the limits are exceeded, double vision, blurring, and apparent movement of print can occur. Convergence insufficiency is common with post-concussion syndrome and is associated with amplified symptoms in this population.

 

Lenses, prisms, optometric vision therapy, and modifications of workstations and lifestyle are necessary to treat binocular vision dysfunctions. There must be adequate rest. Each visual system has its own tolerance for how long it can stare at illuminated screens without symptoms. Many work stations are set up poorly and people often do not take sufficient breaks. Children often have excessive homework in the early grades.

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Adequate treatment requires that eye alignment, focusing, and tracking become automatic and sustainable for extended periods of time. Being able to consciously align your eyes is not adequate. We cannot think about our eyes and simultaneously think about what we are doing. Analogously, I can still run, but ball sports do not work well when getting to the ball uses attention needed for deciding what to do and doing it when I get there.

Optometric vision therapy uses techniques to develop accurate eye movements and perception supported by practice at home to develop automaticity. Trying harder may work for a time, but performance will be inconsistent and cannot be sustained. When treatment is continued to completion and appropriate visual habits are maintained, these problems should not recur.

Convergence Insufficiency Symptom Survey

 

Other blogs you may find interesting:

Vision and Learning: A Guide for Parents and Professionals

Copying

Have Smartphones Destroyed a Generation? by Jean M. Twenge

Adding Vision to Concussion Testing

 

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Smart Moves:Why Learning is Not All in Your Head

    Carla Hannaford

After hearing Carla Hannaford quoted many times, I decided that it was time to read this book and I was not disappointed. I started summarizing and excerpting books years ago to share with staff, but one of the primary benefits was to slow down my reading and to allow me the time to think more deeply about the implications of the author’s words. If you follow our blog, you have come across the understanding that thinking is not all in your head. We would have little difficulty with that if we didn’t already “know” that that all learning takes place in our brains. Changing our thinking, our beliefs, and our actions is much more difficult than learning when it does not require unlearning. I hope that the following excerpts cause you to pause as they have me.

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We have missed a most fundamental and mysterious aspect of the mind: learning, thought, creativity and intelligence are not processes of the brain alone, but of the whole body. Thinking and learning are not all in our head. On the contrary, the body plays an integral part in all our intellectual processes from our earliest movements in utero right through old age. It is our body’s senses that feed the brain environmental information with which to form an understanding of the world and from which to draw when creating new possibilities.

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Neural connections can be altered and grown only if there is full attention, focused interest in what we do. In three weeks we can get ten times more proficient at anything if we are emotionally engaged with focused interest. Self-initiated movement, exploration, interaction and physical experience for the joy and challenge of it, facilitates neurogenesis (nerve growth) for a lifetime. (This has been proven over the last decade when it comes to treating amblyopia. Intensive visual tasks for 20 minutes are more effective than hours of patching without a challenging, engaging activity.)

What we know, feel, learn, and think is shaped by how we know, feel, learn, and think. How we do these things is in turn dependent on the sensory-motor systems though which all our experience of the world and of ourselves is mediated. These sensory-motor systems shape our experience, and are shaped by it. So the story of how these systems unfold is a vital key to understanding learning.

Our proprioceptive sense constantly sends feedback to the brain that readjusts the balance of our shoulder and neck muscles in order for the eyes to remain level while reading.

Touch, hearing and proprioception are important organizers of the visual aspects of learning. Vision is a very complex phenomenon, with only a small percentage (less than five percent) of the process occurring in the eyes. The other over ninety-five percent of vision takes place in the brain from the association with touch, hearing, and proprioception.

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It’s easy to forget, or ignore, how much of vision is learned. We have to train ourselves, through books, movies, and art to see three dimensions in a two-dimensional space. We could call this visual literacy.

The eyes must be actively moving for learning to occur.

Words can only be understood when they provoke some kind of image in the mind of the learner. If students cannot access the underlying images, the words are not comprehensible; there is no context or visual understanding.

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Computer scientist David Gelernter makes this point emphatically: “Emotions are not a form of thought, not an additional way to think, not a special cognitive bonus, but are fundamental to thought.” Gelernter goes on to assert that emotions are also “inextricably tied up with bodily states. The bodily state is part of the emotion, feeds it and helps define it. This means that ultimately you don’t think just with your brain; you think with your brain and body both.”

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One of the most important things a teacher can do, especially with students with disabilities, is to bond with them. CAT scans show that children process information through their emotions first, and information that is the most emotional and emotionally relevant to them, is what students will learn. On the other hand, insecurity and fear can bring learning to a screeching halt by shutting down higher brain connections.

Another unnatural challenge has to do with learning to print block letters as the first step in writing. Printing is a highly linear process that takes us away from the more continuous rhythmic flow of language, both as it is experienced in the mind and as it is expressed through the hand – as in cursive…. Part of the problem is hand development, and asking children to perform the complex process of printing, way too early. In order to print the child must first crawl for a good long time with hands forward, to develop the bones in both the hand and to gain upper arm strength…. If you look at an X-ray of hand development, you will notice that the very intricate bones of the area near the wrist – the carpals, are not fully developed until about age twenty. The more developed these bones, the easier to hold a pen or pencil to print. If the child has had a lot of sensory-motor activation of the hand, printing can be more easily taught at about ages eight to ten.

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Children who have looked at books in the home may have already acquired some foveal focus if the process was their choice and free of stress and pressure to perform, however, most children are not physically ready to read at age five as is now mandated in our schools.

Having been flooded a number of times, flood analogies come to mind. Trying to rush development is like trying to pump the water out of your basement before the level of the ground water goes down. You waste a lot of time and effort if you start too soon because the water keeps coming back in. You are eventually successful when the water (or the child) is ready. It is easy to fool yourself about the influence that you had be starting early. If we try to push children too early, we can also create failures as some children become confused and frustrated who would have done fine when they were ready and interested. Combined with this is the opportunity cost of what these children could have been doing and learning to enrich their experiential background prior to the vicarious experience that we get through reading. There is so much that can be experienced and learned in an interesting, interactive classroom. They can even go outside the classroom where most real learning takes place.

You may think that it is a contradiction for me to disparage in any way the potential to learn through reading but we learn very little when we read about things we don’t already know quite a bit about. This book is a good example. It would have glossed off me forty years ago when I knew that all learning took place in the brain. Decades of experience has enabled me to take information from this book that I could not have understood earlier in my career.

Welcome to Your Child’s Brain

Thinking Goes to School:Piaget’s Theory in Practice

Tummy Time

Visual Factors in Reading

When will identifying vision problems that affect learning become a new standard of care?

 

Thinking Goes to School:Piaget’s Theory in Practice

Hans G. Furth and Harry Wachs

There has always been a temptation to ignore the influence of child development. Development takes time; not everyone develops at the same rate; and all areas may not develop on the same schedule within one individual. There is an increased temptation to ignore development when there is pressure to push students to meet short-term academic goals. Continue reading

Spelling

It is not a coincidence that recognizing faces and remembering the related name correlates with the ability to learn letters, numerals, and words. They all require vision and language, they all require explicit memory, they all require attention to detail while simultaneously seeing the whole, and they all rely on the ability to automate these functions so they take place accurately, quickly, and subconsciously. Continue reading

Handwriting

Being able to write comfortably, quickly, and automatically is still an important skill in the digital age. Attending to the details of letters as we learn to form them also supports learning and remembering their names. Poor handwriting is a common, and logical, reason for children to be referred for an assessment of their vision. Continue reading

The Power of Handwriting

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The Wall Street Journal; April 5, 2016

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This article describes the differences in learning between college students who take notes using a computer and those who take notes by hand. Research studies from Princeton University, UCLA, the University of Nebraska, Harvard University, and Washington University in St. Louis all found that students could type lecture notes faster than they could write them. But they also found that the students who wrote their notes remembered more information about the lecture one week later than if they had typed their notes. (Note: this does not relate to copying notes verbatim as children are asked to do from the Smart Board. For many children, the components of this task are so difficult; looking back-and-forth, keeping their place, writing, and spelling, that they don’t have adequate working memory reserves to attend also to what they are writing.) Continue reading

The Slow Learner in the Classroom

 

Newell C. Kephart was an important figure in the perceptuo-motor school of education and remediation. While education now places less emphasis on perceptuo-motor development, other than in special populations, it is still part of how processing is viewed by psychology and optometry. Occupational therapy and physical therapy have also become involved. Continue reading