Focusing Problems Illustrated
- Doug Cook
- Jan 27, 2009
- 1 min read
Problems with focusing (accommodation) are frequent causes of vision problems in children and adults. Different varieties of focusing problems are simulated below as they would appear to a child at their desk in the classroom. Symptoms of problems in this category include:
Comprehension reduces as reading continued: loses interest too quickly
Mispronounces similar words as continues reading
Blinks excessively at desk tasks and/or reading; not elsewhere
Holds book too closely: face too close to desk surface
Avoids all possible near-centered tasks
Complains of discomfort in tasks that demand visual interpretation
Closes or covers one eye when reading or doing desk work
Makes errors in copying from chalkboard to paper on desk
Makes errors in copying from reference book to notebook
Squints to see chalkboard, or requests to move nearer
Rubs eyes during or after short periods of visual activity
Fatigues easily; blinks to make chalkboard clear up after desk task
Accommodative Insufficiency
Accommodative insufficiency occurs because of the eye can not maintain clear vision at near.
Ill-Sustained Accommodation
Ill-sustained accommodation is similar to accommodative insufficiency except print may initially appear clear and easy to read without effort. With time, the task at near begins to require more effort to focus. Blurred vision, eyestrain and headaches can occur with sustained effort. A simple visual acuity test at near (as what is frequently done during a vision screening) will usually not detect this problem.
Normal Focusing
Our focusing system is usually quite fast at focusing. Most people can focus at near in about 1/5 of a second as simulated above.
Accommodative Infacility
With accommodative infacility, there is a delay in the clearing of the print. The simulation above shows how a student with this problem would be slowed. Copying information from a chalkboard to your desk is a frequent activity in a classroom. It takes the student longer to obtain and transfer the information.
For all of the above problems, lenses or vision therapy or a combination of both may be prescribed. The success of treatment is quite high. A few cases may require only short term use of lenses or vision therapy while others may have a need throughout their youth for this type of help.
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