People with this condition have difficulty converging their eyes to look at a close target, such as when reading. This type of visual problem causes misalignment of the eyes, resulting in double vision unless the individual exerts additional convergence effort to re-align the eyes. As the visual system attempts to eliminate this double vision by using additional convergence effort, a number of significant symptoms can occur.
These symptoms include: frequent loss of place, loss of concentration, having to re-read, reading slowly, trouble remembering what was read, sleepiness, blurred vision, doubling of print, letters or words can get in the wrong order, headaches, and/or eyestrain during reading or other near work, leans in close to computer screen, difficulty copying off the board at school.
During a recent extensive study on this condition in the US, the Convergence Insufficiency Treatment Trial (CITT study) gathered important data about the symptoms of convergence insufficiency in a series of studies. These were the first studies that used a scientifically valid and reliable symptom questionnaire.
These studies found children with convergence insufficiency reported the following symptoms occurred “fairly often” or “always” while reading or doing close work:
Loss of place: 50%
Loss of concentration:45%
Re-reading the same line: 45% Reading slowly:40%
Trouble remembering what was read:38%
Words blurring: 36%
Double vision: 32%
Eyes hurt: 31%
Eyes feel tired: 30%
Eyes feel uncomfortable: 29%
Eyes feel sore: 21%
Words move/jump/swim: 20%
Pulling feeling: 11%
An interesting finding from these studies was performance related symptoms (i.e., loss of place, loss of concentration, re-reading the same line, reading slowly, trouble remembering what was read or feeling sleepy) occurred more frequently than eye related symptoms (i.e., blur, headache, diplopia, or asthenopia). This finding is important because it demonstrates children and adults with convergence insufficiency are likely to experience performance problems when reading.
It is also important to note the second most common symptom was loss of concentration with almost half of the children reporting this symptom “fairly often” or “always” when reading. This potential link between convergence insufficiency and attention disorders has important practical implications for educators, physicians, psychologists other professionals involved in the detection, diagnosis, and treatment of attention deficit hyperactivity disorder.
It suggests a comprehensive vision examination should be mandatory for any child with a suspected attention problem to rule out convergence insufficiency.
Treatment Options for CI
For many years, optometrists, ophthamologists and orthoptics have offered an activity called "pencil to nose! exercise, where a pencil is initially held at arms length and slowly brought in towards the nose until binocular vision breaks down and two pencils are seen - this activity repeated several times during a session and carried out on a daily basis
The CITT study showed this "pencil to nose" activity was NO better than a placebo!
The CITT study also compared home therapy against in-office therapy.
Their conclusion was the only statistically successful therapy was in-office vision therapy
Our research into this condition has shown that CI is linked to many other visual conditions including reduced peripheral awareness, accommodative dysfunction, pursuit and saccadic eye tracking and more
At Shaylers Vision Centre, we regularly carry out optometric vision therapy to not only treat CI, but all the associated problems at the same time using in house vision therapy, and, because we use syntonic phototherapy, we are able to normalise convergence performance in most people in less than 3 weeks!
We are also able to help many of these children using special lens/prism designs which are prescribed by less than 50 UK optometrists, but are more commonly used in the US - see the video below
This video shows a young lady with a mild CI problem demonstrating a lot of stress, (watch her eye lids) trying to look at a pen as it moves towards her face. With her glasses on, using these special low plus prism spectacles, there is no longer any effort needed to follow the pen.
(I would like to thank this young lady and her mother for allowing me to post this video)
This is a similar stress related condition,but in this case, the person is putting too much effort into convergence and the eye overturns. This will lead to similar symptoms to CI