Binocular - Eye Teaming Problems
Convergence Excess (Overconvergence)
The conventional definition is that the eyes turn inwards toward each other in an excessive amount when focusing on an object at close distance.
If your eyes tend to do this you may experience blurred vision, intermittent double vision, headaches, eye strain and fatigue.
Jill was a 17 year old high school student who was referred because she wasn't doing well on her standardized testing. Her grades in all her subjects were all good but when she had to take long timed tests she did poorly and got headaches. Her visual examination showed that she had 20/20 sight in both eyes at distance and near but when I checked her eye teaming ability at near she showed a tendency to over converge her eyes. A pair of reading glasses was prescribed to help take the strain off her eyes while doing close work along with visual therapy to help her eyes be more flexible. After receiving her glasses and doing her visual therapy her standardized test scores for college entrance went up 200 points
Convergence Insufficiency (Under convergence)
The conventional definition is that in doing close work it is necessary for the eyes to turn inward towards each other (convergence) as well as to focus on the object (accommodation or focusing). When the ability of the eyes to converge is inadequate it is called convergence insufficiency.
If your eyes tend to do this you may experience blurred vision, double vision, headaches, eye strain, burning of the eyes, excess tearing.
Scott was a 10 year old boy who was having problems in school. Though highly verbal he just didn't like to read. He would start to read and less than five minutes later he would get up and do something else. His mother was worried since he was becoming a behavior problem at school and he was failing reading. He had been to the eye doctor but had been given a clean bill of health saying he saw 20/20 and his eyes were healthy. After the visit with me, their next stop was to the pediatric neurologist to see if medication could help.
His examination revealed 20/20 sight at distance and near and healthy eyes, but he did also show a convergence insufficiency, this eye condition made it extremely difficult to focus on near tasks ex. reading for extended periods of time. No wonder he didn't like to read. I explained to his parents that glasses wouldn't help but that visual therapy to teach his eyes to be able to focus at near without strain was recommended
After a home based six month vision therapy program Scott's behavior in school and his grades both improved significantly as he now had the ability to focus his eyes on a near task for an extended period of time.