By Michele R. Bessler, O.D. and Martin H. Birnbaum, O.D.
Current research indicates that approximately one out of four children have vision disorders that interfere with their ability to learn. Even if a child passes the standard basic vision exam with 20/20 visual acuity, it is still possible to have inefficient visual function which affects learning. Many visual skills and abilities are vital to the learning process, yet are not tested for in routine eye exams that primarily test for 20/20.
Children who are behind in school need to have a specialized evaluation, by an optometrist who specializes in vision therapy, to rule out hidden vision disorders that interfere with learning. Parents and teachers are frequently unaware of the existence of such disorders, because the child can read the 20/20 line on the eye chart. Nevertheless, hidden vision disorders can challenge the child’s ability to learn on an ongoing basis.
Children who struggle to read and complete assignments, or who become disinterested in and avoid reading, often have vision disorders which underlay these problems. Eyestrain, blurring, headaches, double vision, “words moving on the page”, loss of place, failure to recognize letters or simple words, omissions and transpositions, difficulty copying from the desk or chalkboard, and inability to sustain attention while reading are common symptoms of such vision disorders.
Among the vision disorders that commonly interfere with classroom performance are inadequate binocular eye coordination and focus abilities. These conditions typically cause blurred vision, eyestrain, headaches, and double vision when reading. Because it is difficult to focus on individual words, children with these problems often lose place frequently, omit words, close one eye, and show difficulty sustaining reading for long periods. Comprehension often suffers as a result of excess effort required to make the print clear and single. Many children struggle unnecessarily, require excessive time to complete assignments, or simply avoid reading.
Deficits in visual tracking may also interfere with classroom performance. Inadequate visual tracking causes jerky and inaccurate eye movements when reading, loss of place, poor copying skills, a need to use finger or marker to keep place, misaligning digits in columns of numbers, and difficulty with Scantron test answer sheets.
Visual perceptual deficits should be suspected when a child confuses similar looking words, fails to recognize words previously learned, or fails to demonstrate adequate sight recognition. Excessive reversals are also a common sign of vision perception disorder. Since these deficits interfere with reading in the earliest stages of learning to read, they should be particularly suspect in the child whose reading problem began in the first grade. Visual perceptual evaluation tests the child’s ability to make visual judgements, recognize and remember shapes and forms, see similarities and differences, and process visual information.
Since children with disorders of two-eye coordination, focus, visual tracking, and visual perception frequently have normal eye health and 20/20 eyesight, their visual function deficits are frequently not diagnosed, even during a routine examination. Detection and diagnosis require a specialized evaluation that goes beyond the ability to read the eye chart. Such an evaluation is performed by optometrists who specialize in vision therapy.
When these vision disorders are detected, they are usually treatable, often with significant gains in classroom performance. Although optometrists do not treat learning problems, the elimination of vision disorders that contribute to learning difficulty often allows a child to more readily achieve his or her potential with appropriate educational remediation.
When these vision disorders are treated, many parents report not only that their children’s symptoms of eyestrain, blurred vision, loss of place, copying difficulty, and double vision have been resolved, but that they are also doing much better in reading and in school. Further, children frequently complete homework more easily, begin to enjoy reading for the first time, experience less frustration with school work, are more self-confident, and exhibit greater self-esteem. Parents frequently report less tension in the family, as the child experiences less frustration, behavior issues reduce, and parents are not so extensively occupied with having to help the child with school work.