If you have any question about the influence of how we evolved on our health, I hope that the following information from The Story of the Human Body by Daniel E. Lieberman convinces you….
We make many decisions every day. There is no data for most of the decisions that we make and when there is, there is a good chance that we interpret them incorrectly. Because important decisions about health and healthcare are made based on statistics, it is important to understand relative and absolute risks and what the numbers really mean. Here is what the author has to say…. Continue reading
Scanning is used to find an object, a person, or a word. This is usually simple for most adults, but not always (such as men looking into a refrigerator). As is true for many skills that have become automatic, it is easy to overlook the complexity involved and how difficult it is to learn.
Scanning requires sequential eye movements and fixations. It requires visualizing the desired object and maintaining that image while looking at other objects. This is particularly challenging if the other objects are either distracting or similar to the object in question. When this is the case, the load on working memory increases and it becomes more difficult. If we are looking for our sneakers, that is one level of challenge. If we are looking for tomato soup amongst other soups or a phrase on a page, that is very different. It can be like singing one song while listening to another. If the eye movements are random, the fixations too brief, or if the visualized image fades, we will not succeed. Scanning requires sustained vigilance.
The inability to scan efficiently wastes time and is frustrating. The quality of scanning reflects a person’s organization. They are both disciplined, sequential, and require working memory. Academically, scanning is important when we are copying so we can find our place when looking back-and-forth. It is important when finding information, such as answers to a question in a passage that has been read. If a child needs to start to read a passage over, it will be time-consuming and they will inevitably forget what is was that they were looking for. Scanning requires the integration of top-down processing (keeping the image in working memory and filtering everything else that is seen) and bottom-up processing (directing the eyes with a goal-oriented priority). Scanning is one of the skills developed in optometric vision therapy.
What it Means to be Alive
By, Brian Christian
This is truly an unusual book written by an author who could be considered a young Renaissance Man or polymath. Brian Christian has a dual degree from Brown University in computer science and philosophy. He also has a MFA in poetry from the University of Washington. Alan Turing stated in 1950, that computers would be thinking one day. The impetus for Christian’s research and the book is the Turing test in which judges are challenged to distinguish who is human and “who” is a computer. An annual competition commenced in 1991, and the computers almost won in 2008. Brian Christian was chosen to be one of the humans competing in 2009. In trying to prepare to prove that he is more human than the computers, his preparation takes him into the area of language and also into the question of what it is that makes us human. The book is informative, insightful, and entertaining. Continue reading
I have blogged previously about Dyslexia, Fluency, and the Brain which was edited by Maryanne Wolf. She has been a leading researcher on the processes of reading in the brain for decades. I have chosen the following excerpts from this book for their appreciation for how reading develops which provides insights into how reading readiness and reading instruction can be improved…. Continue reading
How to Take Charge of Your Child’s Education
Susan Wise Bauer
Susan Wise Bauer is qualified to write about school and education. She is the author of 13 previous books and co-author of another, all on learning and education. She was home-schooled and home-schooled her children. She has practical experience on how educational systems work. If you and your child are struggling within the system, Susan Wise Bauer has practical recommendations to improve the fit between your child and the system. As she states: “Schools exist to serve children, not the other way around.” She also shares recommendations on homeschooling if that is your choice. Continue reading
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.
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.
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.
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.
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.
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.
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