Memories of my aged mother complaining that she could see two images of the same person on the TV screen makes me wonder what causes double vision? And, I wonder, how many children are being medicated for attention deficit hyperactive disorder when the trouble is in their eyes?
Dr. Patrick Quaid, an expert in double vision, is head of the Guelph Vision Therapy Centre. He says that double vision must be taken seriously because its causes can range from brain tumour, concussion or inflammation of an artery to simple dysfunction of ocular muscles. Fortunately, when adults notice DV, they know something is wrong and demand quick attention.
But Quaid says children with ADHD often get either a delayed diagnosis or no diagnosis of ocular disorder. Doctors treating a child with ADHD rarely consider arranging for an eye examination to detect ocular malfunction.
The most commonly encountered abnormality is “convergence insufficiency,” or difficulty keeping the eyes tuned when reading. These kids’ eyes 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 often misdiagnosed as sinusitis or migraine.
A major trap can lead parents and doctors astray. Quaid says that after a regular eye test — which largely tests each eye separately — children with convergence insufficiency may appear to have 20/20 vision. Yet the child still sees double when trying to focus on something up close. And children rarely complain of any problem. Although their vision is abnormal, it is, to them, their normal vision.
Convergence insufficiency is not rare. Quaid says that one in 10 people has some sort of eye-teaming problem. But what is shocking, and generally unknown, is that children showing signs of ADHD are three times more likely than other kids to have convergence insufficiency.
That’s why any parents who are investigating whether their child has ADHD should also arrange for the child to see an eye specialist with expertise in eye-teaming abnormalities.
Quaid adds that doctors often place ADHD children on Ritalin, or some other medication, without arranging for a detailed oculomotor examination.
Quaid also discussed another cause for concern: Post-Trauma Vision Syndrome. Today, the risk of concussion is a fact of life for children and adults involved in contact sports. Moreover, bruised brains can result in serious neurological and ocular abnormalities despite normal results from MRI and CT scans.
Quaid’s advice for those who intend to engage in contact sports: Get a baseline test for binocular vision function before engaging in contact sports. This is important as those who already have binocular vision dysfunction, and may not realize it, will likely suffer even greater eye-teaming issues should they suffer a subsequent concussion.
In fact, a concussion may be like the straw that breaks the camel’s back, causing more severe and less treatable problems.
Just how many children in this country are being diagnosed with ADHD when they in fact suffer from vision problems is unknown. But we do know that too many children are being placed on Ritalin for questionable reasons.
Surely it makes sense to arrange for an eye examination specifically looking at eye-teaming skills before doing so.
The difficulty for parents is that children will usually not complain of problems with eye-teaming as they may not be aware of what to report. This may result in misdiagnosis.
The Guelph Vision Therapy Centre is an excellent example of a clinic that offers a comprehensive approach to ADHD and eye-teaming problems. This involves close interaction between eye doctors with experience in binocular vision disorders, psychologists, speech and language pathologists and occupational therapists.
Look online for a doctor in your area who treats eye-teaming disorders.