This is the most common eye muscle disorder among children and adults, 80% of children with reading difficulties have convergence insufficiency or similar vision problems.
Convergence Insufficiency (CI) is a binocular (two-eyed) vision disorder in which the eyes do not work at near easily. An eye teaming problem in which the eyes have a strong tendency to drift outward when reading or doing close work. If the eyes do drift out, the person is likely to have double vision. To prevent double vision, the individual exerts extra effort to make the eyes turn back in (converge). This extra effort can lead to a number of frustrating symptoms which interfere with the ability to read and work comfortably at near.
Individuals with convergence insufficiency will often experience:
- eyestrain (especially with or after reading)
- blurred vision
- double vision
- halo effect
- inability to concentrate
- short attention span
- frequent loss of place
- squinting, rubbing, closing or covering an eye
- sleepiness during the activity
- trouble remembering what was read
- words appear to move, jump, swim or float
- problems with motion sickness and/or vertigo
Convergence insufficiency is very common in children with a diagnosis of ADHD. It generally does not interfere with learning how to read (word recognition and decoding), but can interfere with reading comprehension and fluency, especially as children are expected to read for longer periods of time.
Convergence insufficiency is present in 2.5% to 13% of children and adults. While the good news is that convergence insufficiency responds well to proper treatment, the bad news is that – due to lack of testing for CI – many people are not getting the help they need early in life. This testing is not included in (1) eye tests in a pediatrician’s office; (2) school eye screenings; and/or (3) standard eye exams in an optometrist’s, ophthalmologist’s or optician’s office. A comprehensive vision evaluation by an eye doctor who tests binocular (two-eyed) vision and who can refer or provide in-office vision therapy is recommended for all individuals who exhibit any symptoms of convergence insufficiency.
This occurs when the natural posture of the eyes is closer in than required for near vision tasks. This means the individual, when they look to near vision tasks, has a natural tendency to aim the eyes closer in than the position they are trying to aim at.For example, when someone is reading their eyes should ideally be aimed and focused on the words on the page. In cases of convergence excess, the eyes would actually aim and focus at a point closer in than the page itself. Often individuals with this can be seen to hold themselves closer to the page or object than is usually necessary.The signs and symptoms associated with convergence excess are often related to prolonged, visually-demanding, near centered tasks such as reading. They may include, but are not limited to the following:
- Eye Strain
- Avoidance of or inability to sustain near visual task
- Double vision
- Blurred vision
- Poor posture/abnormal working distance
- Pain in or around the eye
- Eye fatigue
Without effective management myopia (shortsightedness) can often result in later years, such as in high school.