HOUSTON, Apr 10, 2009 (UPI via COMTEX) -- An eye muscle coordination disorder
-- convergence insufficiency -- if left untreated, often affects school
performance of students, a U.S. eye expert says.
The disorder is found in some 5 percent to 20 percent of the population,
depending on the definition used and the age group studied, Dr. Janice Wensveen
of the University of Houston College of Optometry said.
"As the name implies, it's somebody who can't cross their eyes, and you might
think that's a weird thing to have to be able to do," Wensveen says in a
statement. "But, if you just consider the geometry of looking up close, your two
eyes do have to turn in so that they're both pointing at the thing that you want
to see."
Symptoms of convergence insufficiency include loss of place and concentration
while reading, reading slowly, eyestrain, headaches, blurry vision and double
vision.
For those with the disorder, reading can become very frustrating.
"Studies would suggest there is a possible relationship between convergence
insufficiency and attention-deficit hyperactivity disorder, in that about 10
percent of patients with convergence insufficiency had a history of ADHD at
initial presentation or in follow-up exams," Dr. Nick Holdeman, executive
director of the University Eye Institute at the University of Houston said.
"While the research does not support a direct relationship between the two
diagnoses, it is recommended that evaluation of convergence insufficiency should
be undertaken in children diagnosed with ADHD."
URL: www.upi.com
Copyright 2009 by United Press International