“I’ve just seen two images of the same person on the TV screen,” my aging mother complained years ago. She had developed double vision. But what causes this condition? And how many children suffering with attention deficit hyperactive disorder (ADHD) are being needlessly medicated when the trouble is in their eyes?
Dr. Patrick Quaid, head of the Guelph Vision Therapy Centre, is an expert in double vision. He says that double vision must be taken seriously, as its diagnosis can range from brain tumor, concussion, or inflammation of an artery to simple dysfunction of ocular muscles.
Fortunately, when adults notice double vision, they know something is wrong that demands quick attention. But Dr. Quaid says children with ADHD often get either a delayed diagnosis or no diagnosis of ocular disorder. In addition, doctors treating a child with ADHD rarely consider arranging for an eye examination to detect ocular malfunction.
Convergence Insufficiency
The most commonly encountered abnormality is “convergence insufficiency,” or difficulty keeping the eyes tuned when reading.
These children have eyes that do not work in unison due to an imbalance of muscle control. Consequently, they see double when reading, frequently lose their place, find reading frustrating, and shy away from it, which affects their learning. They’re also inclined to rub their eyes and suffer from frontal headaches that are misdiagnosed as sinusitis or migraine.
A major trap can lead both parents and doctors astray. Dr. Quaid says that ironically parents of children with convergence insufficiency may be told their child has 20/20 vision by a regular eye test. Yet, the child still sees double when trying to focus on things that are close.
The disconnect is that children may not complain. Although their vision is abnormal, to them, it is their normal vision.
