You may be familiar with the term “acuity,” but it’s only one part of a healthy visual system. There are a number of other visual skills that are also critical, and if these aren’t working correctly, school problems can result.Visual acuity is defined by the American Optometric Association as the “clarity and sharpness of vision.” It is only one component of a healthy visual system, which includes the eyes, the brain and all the visual pathways. For effective vision to take place, all of these physical components must work together, helping a person utilize vision and make sound judgments based on what they encounter.
A learning problem, for example, may occur in someone who tests 20/20, but has a binocular vision disorder that won’t allow their eyes to work together when reading. This is the reason so many vision problems go undetected. The testing simply is not far-reaching enough to tap into all the vision problems that can affect learning.
Dr. Kellye Knueppel of The Vision Therapy Center finds that many teachers, school nurses, physical therapists and learning disabilities professionals are shocked to discover that a child with 20/20 visual acuity can have a profound vision problem, and subsequently, a learning problem. “It’s surprising, but 25% of children have a vision problem that can affect learning,” Knueppel said. “Reliance on the Snellen eye chart for vision screenings is why the vast majority of these problems go undetected.”
What Should a Vision Test Include to Help Pinpoint a Learning Problem?
A comprehensive approach is critical when testing for eye issues. In addition to visual acuity, she believes the following items must be included in the testing process: Alignment of the eyes, binocular depth perception, eye movements necessary for reading (‘tracking’), magnitude and flexibility of accommodation (‘focusing’), visual motor integration and visual perceptual abilities. “From there you can start to narrow in on a particular vision problem, if one exists,” Dr. Knueppel points out.
The problem with this wide range of tests, as opposed to the limited screening conducted at school, is that school staff doesn’t have the training or the equipment necessary to conduct the tests. It’s why Dr. Knueppel believes that understanding the symptoms behind typical vision problems is critical for parents and educators.
“If you see a child rubbing his or her eyes, avoiding reading, getting close to the book when reading or complaining of headaches or eyestrain, it should be a warning sign that more testing is needed,” Dr. Knueppel said. “From that point, the burden is on the parent to act and help uncover the true source of the learning problem.”
Knueppel recommends finding a developmental optometrist that pairs with general practice optometrists. “Generally speaking, an optometrist can perform the tests required to spot the problem, but often doesn’t have the time or equipment to do so. Parents will need to ask specifically whether or not the optometrist does all the tests needed to rule out functional vision problems,” she said. “In 25% of the cases, you’ll probably need to visit a developmental optometrist for a functional vision test.”
A Functional Vision Test is beneficial because so many vision problems are hard to detect, and often children don’t realize they have any issues. Expanding the search beyond visual acuity could help you find these problems, and potentially discover the root cause of a child’s learning problem.
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