The first visual disorder I want to go into more detail about is convergence insufficiency. It is among the most (if not the most) common binocular vision disorder we treat at The Center for Vision Development. Optometrists Network states that it is the leading cause of eyestrain, blurred vision, double vision, and/or headaches. Convergence means to come together and meet at a point. So, convergence insufficiency is the inability of the eyes to turn inward enough to focus on a close target. It entails the inability of the eyes to work together in a simultaneous, coordinated manner. This affects one’s capability to do near work such as reading, writing, and computer use.
The tendency of the eyes to drift outward means they are essentially looking past the focal point. Many who experience this work extra hard to turn their eyes inward to eliminate double or blurred vision, which can not only cause eyestrain and headaches but also poor concentration and comprehension, tendency to lose one’s place while reading while also experiencing the words float or jump around the page.
The negative impact these symptoms can have on a person’s daily life, especially a child in school, is obvious. So how is this visual disorder not more widely known? According to the Optometrists Network, “A person can pass the 20/20 eye chart test and still have convergence insufficiency”. Also, if a child has convergence insufficiency, they might not know that what they see is abnormal because it is all they know.
Concurrently, the child may not know how to communicate what they are experiencing. It is challenging for anyone to communicate exactly what their eyes are doing, especially a young child. This visual challenge often manifests itself through behaviors and habits that are very similar to attention and learning disorders, laziness, and an aversion to reading and learning.
Aside from the unhealthy behaviors and habits which stem from the symptoms, a person can have convergence insufficiency yet not complain about any of the aforementioned symptoms. This happens when a person’s brain has essentially found a way to cope with double vision by halting communication with one eye. The eye can still be perfectly healthy, yet it is not taking in any information. This is called suppression, and it is the brain’s subconscious effort to eliminate the symptoms of binocular vision disorders. This is equivalent to someone covering or closing one of their eyes when doing close work, which can also be a coping mechanism for someone with convergence insufficiency.
Through weekly vision therapy sessions and at home therapy, we are able to train the eyes to turn inward. This process takes time and numerous methods, but I’ll delve deeper into one of those methods in order to give you a glimpse into effective treatment. After patching, and after each eye has proven successful on its own, we begin binocular work. One of the first things we do to begin treating convergence insufficiency is called physiological diplopia. This practice teaches the brain what normal double vision is supposed to look like.
To do this, we have the patient put an object such as a writing utensil or their finger about six inches away from their face and then choose a distant object across the room. When looking at the object/finger closest to their face, they should see two of the objects in the distance and vice versa. Those with convergence insufficiency or CI, will initially struggle to see only one of the close objects because their eyes constantly want to look further in the distance. Those with suppression will not see double at all. This is an important first step for those with a binocular vision disorder to understand what “normal” vision is supposed to look like. From there, we can begin training the brain to have total control over the eyes.
If you think you or your child has convergence insufficiency or any other binocular vision disorder, do not hesitate to call and set up an evaluation with Dr. Taddese. We want every child to have every chance to succeed in school and live up to their potential!
References:
http://www.convergenceinsufficiency.org/
https://www.covd.org/
Scientific Articles:
“Treatment of Convergence Insufficiency in Childhood: A Current Perspective” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2821445/
“Effectiveness of Vision Therapy for Children With Symptomatic Convergence Insufficiency With or Without Attention Deficit Hyperactivity Disorder” https://c.ymcdn.com/sites/www.covd.org/resource/resmgr/VDR/VDR_1-3/VDR1-3_article_Shin_Web.pdf
Convergence Insufficiency Treatment Trial: http://www.covd.org/?page=citt
-Emily Thompson, Vision Therapist
