The now well-known developmental disorders ADD (Attention Deficit Disorder) and ADHD (Attention Deficit Hyperactivity Disorder) are often comorbid with eye issues, and there can be substantial overlap of the symptoms caused by ADD/ADHD and some vision issues. The results of a recent study revealed that over 15 percent of children with vision problems also have ADHD, as opposed to about 8 percent of children who do not have vision problems.
Attention deficit hyperactivity disorder (ADHD) is a brain disorder that affects how you pay attention, sit still, and control your behavior. It happens in children and teens and can continue into adulthood.
There is a correlation between ADHD and underlying vision problems. There's an overlap in a lot of the inattention type symptoms, but not as much of an overlap between the impulse control symptoms. Those are symptoms that aren't as often associated with an underlying vision problem, and are more likely to be ADHD. It is possible that in some cases, a person may receive a diagnosis of ADHD when in fact they have an underlying vision problem that is causing the same symptoms. It is also equally possible that a child could have a diagnosis of both ADHD and an underlying vision problem. Dr. Grant conducted a study where he found that there is a three fold increase in the likelihood of a child with ADHD also suffering from convergence insufficiency, and vice versa. It was recommended in that study that if you or a child have been diagnosed with ADHD, you should take your child to a developmental eye exam to rule out underlying vision problems, such as convergence insufficiency or any eye teaming disorder.
There are a number of other symptoms of vision issues that can be mistaken for ADHD symptoms
Consider a child with eye alignment issues. When they look at text, they see blurry or double unless they put a lot of extra energy into keeping their eyes aligned. The result is that they feel tired after short periods of reading, or perhaps they succeed in reading but their extra effort to just see what they read means they don't have any time or energy remaining to understand what they are reading. They work just as hard as their classmates, but always feel like they are way behind. Will that child continue to work as hard on reading or maybe get restless? If they never understand what they read will they end up acting out or getting restless during class?
It is very important to stress that vision therapy does not fix or deal with ADD. However because ADD and developmental vision delays display many of the same symptoms, and because it has been shown that many children with ADD have a developmental vision delay, it is strongly recommended that any child that displays signs of ADD or has been diagnosed with ADD also undergoes a developmental eye exam.