Parents know that having good vision is a key element in a child’s academic performance. School vision tests are often relied upon to catch any problems. Screening reports of 20/20 vision allow us to dismiss difficulty with seeing as a possible source of less-than-desirable academic behavior and results. The hidden secret here, however, lies in the fact that having 20/20 vision does not mean your child can see well!
Visual Problems Obscured by 20/20 Vision
To many layman’s surprise, there are a number of issues beyond visual acuity that cause an array of problems. The two most common conditions seen in children are insufficiencies in accommodation and in convergence, functions that are not tested in the “read the chart” screenings done at school or even in many professional eye exams. These insufficiencies may cause a person to have difficulty with being able to see, read, learn and work at near distances.
The problems become increasingly apparent around the third grade level, as student textbooks reduce print size with the normal expectation of more highly developed visual skills. As a student is struggling, adults look at a long list of possible reasons in an effort to identify and eliminate the source of the struggles. They usually begin with the symptom: Johnny doesn’t read well, Maria gets headaches and rubs her eyes a lot, nothing can convince little Dana to concentrate on getting that homework done. Even difficulties with physical activities and sports can indicate a concern, as skills such as eye-hand coordination are affected.
The first thing we think of is whether the child might need glasses. Because they have just read the eye chart with a 20/20 result, we reason quite logically that their vision can’t be the cause. On to other possibilities. An attention problem, physical conditions, lack of motivation, etc. A list emerges but nothing quite fits the situation. Frustration and even anger ensue. What might be causing the child to behave in this way?
A comprehensive binocular exam, which includes tests for depth perception, numerous measurements of your eyes ability to move and focus as a team and may include an evaluation of your brain’s ability to perceive the visual input it receives. The conditions of insufficient accommodation or convergence dysfunction can be responsible for a long list of issues and it takes a professional diagnosis and treatment to help your child overcome them.
What exactly do these medical terms mean? Accommodation, simply put, is the eye’s ability to focus. Because we are constantly changing what we are looking at, and looking at objects at varying distances, the focus must happen quickly and repeatedly. If there is a problem in this function, it is referred to as insufficient accommodation.
Convergence refers to our ability to make our eyes work together. Our brain receives two separate images, one from each eye. Bringing these two images together as one is a skill learned in our early years, allowing us to focus on an object or scene. If this skill has not developed sufficiently, problems like double vision or a halo effect occur.
What Treatment is Available?
Both accommodation insufficiency and convergence dysfunction are treatable. Vision therapy is a standard approach for working with both conditions. Use of prisms or lenses is not expected to cure the conditions, but remains an accepted means of relief of symptoms in many cases and while surgical options do exist, they are not recommended except as a last resort.
Vision therapy does not involve muscular training; rather, this approach is based on our brain’s ability to create new pathways for old functions, a capacity known as neuroplasticity. The child’s brain can typically learn new and better ways for focus and binocular vision. Optometric vision therapy is a carefully laid out program of procedures, designed specifically for each patient’s individual needs and supervised by vision care professionals. Therapy is primarily done in their offices, although it may from time to time be supported by procedures at home. Sessions are typically from 30 minutes to an hour and are scheduled once or twice a week.
A clinical trial funded by the National Eye Institute showed that children responded quickly to an established vision therapy protocol similar to that above, with up to 73% either achieving full correction of their vision or seeing marked improvements within 12 weeks.
Based on a study of children in two elementary grades, as many as 13% of children are believed to suffer from convergence dysfunction. Considering the wide-reaching effects this condition may have, a thorough binocular optometric exam is as important a part of your child’s health maintenance as are the annual physical and the dentist’s visit.