The majority of people who have convergence insufficiency are able to see 20/20 on the eye chart, which is why this common binocular vision condition is often missed during vision screenings and regular eye exams. As convergence insufficiency primary affects visual functioning at near, many of the complaints occur during reading, computer work, and other near tasks.
Convergence insufficiency affects vision in several ways, including:
- Double Vision, especially with reading or other near work
Words move, jump, swim, or appear to float on the page
Blurred vision or words appearing to come in and out of focus
Convergence insufficiency causes a number of symptoms, including the feeling that your eyes feel:
Convergence insufficiency also has a number of effects on performance of near tasks, including:
Loss of concentration when reading
Difficulty remembering what has been read
Loss of place when reading
Mistakenly re-reading the same line of text
Due to the connection between convergence and accommodation (eye focusing), up to 58% of children with convergence insufficiency have accommodative dysfunction, or deficient eye focusing skills. When the eye focusing system is not working properly blurred vision results. Blurred vision due to accommodative dysfunction is often intermittent and varies depending on the visual demands of the task. This is why a child may pass a vision screening one day but complain of blurred vision. Blurred vision due to accommodative dysfunction often occurs during prolonged near tasks, such as reading, and when quickly changing focusing distance, such as when taking notes from the board in school.
A correlation exists between convergence insufficiency and learning & attention issues. Children with ADHD, for example, are three times as likely to have convergence insufficiency. Further research into a potential link between convergence insufficiency, attention, and reading abilities is currently under way. Clinical experience has shown that many children improve reading fluency and even attention following proper treatment of their convergence insufficiency. Simply put, it is much easier to read when the words are not moving on the page, becoming double, and blurring in and out of focus. It is easier to remember what you have read when all of your concentration is not devoted to keeping the words on the page clear and single. Reading is also more enjoyable when you do not have a headache and your eyes do not hurt.
DID YOU KNOW? Many of the symptoms of ADD/ADHD are shared with the symptoms of binocular vision dysfunction.
Binocular vision dysfunction, such as convergence insufficiency and ADD/ADHD are NOT the same and the treatment for these conditions is not the same. It is important to rule out a visual condition, such as convergence insufficiency, when going through the process of diagnosing ADD/ADHD. The results of a Binocular Vision Assessment performed by a residency-trained neuro-optometrist will provide valuable information for the pediatrician and other medical professionals on your child's care team.