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.

pexels-photo-620251

 

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.

pexels-photo-838879

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.

girl-squints-reading-in-bed-660x440

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.

pexels-photo-783941

thX4BQH8CI

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.

pexels-photo-262103

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

 

Advertisements

The Heroism of Incremental Care

Atul Gwande is an unusually talented observer, thinker, and writer who is a surgeon. I have blogged about his books in the past. If you are interested in health and healthcare, I think that you will find his article on incremental healthcare to be intriguing. Although it is long, I think that it will hold your interest. It can be accessed through Google.

GJW

The Heroism of Incremental Care/ The New Yorker

 

 

 

 

 

BALANCE

A Dizzying Journey Through the Science

Of Our Most Delicate Sense

Carol Svec

Balance usually works so well that people don’t think about it until we get older. After over eighteen months of research, interviews, being an experimental subject, and writing, Carol Svec concludes, “We don’t have a sense of balance. We are balance. Balance gives us our place and space in the world, but it also contributes to our sense of self.”pensioners-2399602_960_720 Continue reading

The Importance of Sleep

This article is long, but is too interesting to put you to sleep. Research is demonstrating how the brain can heal itself through an adequate amount of natural sleep. The medications which are currently available do not stimulate the brain activity of restorative sleep but new possibilities are being developed. We already know that sleep deprivation is one of the most effective means of torture. Research had demonstrated that our cognitive abilities decline with modest sleep deprivation and getting less sleep is associated with gaining weight. We now have indications that sleep is preventative to the disease process in Alzheimer’s. Sleep is not a luxury. It is a necessity in all animals in which it has been studied.

Sleep 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