ID Vision Problems to Complement Literacy Efforts

Even the best tutoring programs and literacy efforts may result in time and money wasted if hidden vision problems remain undetected. These problems are present in many participants in literacy programs, according to two studies reported by the St. Louis-based American Optometric Association.

In one study, three-fourths of the students in a Virginia literacy program failed a vision screening. The most common difficulty identified during the screening was an eye-tracking problem, which made it difficult for subjects to move their eyes smoothly along a line of print.

In the other study, two-thirds of the students in a literacy program in New York failed the vision screening. In this study, the most common difficulty was the inability to see clearly at a normal reading distance.

Just because your literacy-program students already wear glasses doesn’t mean that they don’t have undetected vision problems. Although most schools screen for these problems today, many older people in the work force may have received screening tests for distance vision only, according to Joel Zaba, OD, who headed the Virginia study. “Many in the adult illiterate population may not have had their learning-related visual problems detected earlier,” he says.

1. Visual Acuity:
   Visual acuity is the ability to see objects clearly. Reading letters on an eye chart only measures how well or poorly the person can see at that distance.
2. Visual Fixation:
   Direct fixation is the ability to aim the eyes accurately when looking at a stationary object, such as reading a line of print in a book.
   Pursuit fixation is the ability to follow a moving object with the eyes, such as reading a sign on a moving bus.
3. Accommodation:
   Accommodation is the ability to adjust the focus of the eyes as the distance between the individual and the viewed object changes. For example, this enables the person to read an instruction manual while working on a machine.
4. Binocular Fusion:
   Binocular fusion is the brain’s ability to gather information received from each eye separately to form a single, unified image. Without this ability, double vision may result. The brain often subconsciously suppresses or inhibits the vision in one eye to avoid confusion. That eye may then develop poor visual acuity. This is known as amblyopia, or lazy eye.
5. Convergence:
   Convergence is the ability to turn the two eyes toward each other to look at close objects. This skill is critical to binocular fusion.
6. Stereopsis:
   Stereopsis is the result of binocular fusion that enables judgment of the relative distance between two objects. Poor stereopsis is an indication of incomplete binocular fusion.
7. Field of Vision:
   Field of vision is the area covered by one’s vision. It’s important that a person be aware of objects on the periphery as well as in the center of the field of vision.
8. Visual Perception:
   Visual perception is the total process responsible for the reception and understanding of visual information.
   Form perception is the ability to organize and recognize visual images as specific shapes. The shapes encountered are remembered, defined and recalled.

Individuals who present some of these visual problems may require nothing more than a pair of glasses before they can get the most out of a literacy program. Other problems require vision therapy to help the student learn to use both eyes together, develop eye-tracking skills or improve other skills needed for reading, says Andrea P. Thau, OD, who headed the New York study. Detection of these problems improves the chances of success of literacy efforts, but uncovering a cause for reading difficulties also has a positive effect on literacy students’ motivation.

Further information on learning-related vision problems is available from:

American Optometric Association
243 N. Lindbergh Blvd.
St. Louis, MO 63141
314/991-4100

A checklist of vision-related symptoms and single copies of a pamphlet, Do Vision Problems Cause Adult Reading Problems? are available. Send a self-addressed, stamped, business-size envelope with your request to the Communications Center at the above address.