When we look at an object our eyes receive that information and send it to our brain to be interpreted and processed. When a child has difficulty making sense of what the eyes “see” it is termed a visual processing disorder. It is possible to have 20/20 vision and still have difficulty processing what is seen, for while we “look” with our eyes, we truly “see” with our brain.
In 1862 Herman Snellen, a Dutch ophthalmologist, developed the Snellen chart (see image on right) which measures visual acuity for distance. In the U.S. that distance is 20 feet. While the Snellen chart is the oldest diagnostic vision test still in use it is, unfortunately, also the most common way in which children’s vision is screened. A child may be able to see the Snellen chart very well at 20 feet with either eye and thus have 20/20 vision, but may not be able to focus the eyes to read at 20 inches. The child may also not be able use the eyes together, may have difficulty separating foreground from background or locating an item in space, may have difficulty judging distance, may miss visual details and social cues, and may have difficulty using vision to guide body movements, etc.
Problems that affect visual perception and organization may sometimes be difficult to recognize. However, they can have a very significant effect on academic achievement as well as motor skills and behavior. The following are some common behaviors that often indicate a child is experiencing problems with vision processing:
Symptoms of Visual Processing Problems
- Loss of attention and concentration, easily distractible
- Day dreaming
- Poor handwriting, difficulty writing on lines or keeping margins
- Clumsiness, bumping into things, inability to catch a ball, etc.
- Difficulty copying information from the board or a book
- Loses place or skips words when reading
- Difficulty with similar patterns or shapes and/or similar letters or numbers (e.g., q/p, d/b, 9/6)
- Blurring of vision during and/or after reading
- Lack of retention of written material, or visual teaching aids
- Problem solving difficulties
A comprehensive assessment of a child’s vision may include evaluation of eye tracking, eye teaming, fusion, depth perception, near and distant visual acuity, visual motor skills, visual closure, visual contrast, visual discrimination, etc.
Treatment may involve glasses, therapeutic activities to do at home, vision therapy, prism glasses, etc. For more information concerning the evaluation and remediation of visual processing problems, please read about the Padula Institute’s “Learn to See” program.