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Convergence Insufficiency

What Is It?

Eye teaming problems (technically known as Convergence Insufficiency) is when you have trouble keeping both eyes turned in to point in the same position when you are doing close work like reading, writing, computer work.

People who can't keep their eyes converged generally have very few visual symptoms. However they do tend to have poorer fine eye-hand and visual motor skills and may avoid near-centred tasks.

The Science....

Doctors and scientists agree that the evidence is so strong now for the treatment of Convergence Insufficiency (CI) that follow-on studies are beginning to look at the effects the CI directly has on issues which affect quality of life (QOL). 


In this vein, there is currently a very large program underway in the USA led by optometrist Professor Mitchell Scheiman to continue the work of the optometry and ophthalmology collaborative work of the Convergence Insufficiency Treatment Trial: Attention and Reading Trial (CITT-ART)[i]. This is a major randomized clinical trial evaluating the effect of vision therapy on reading and attention in school-age children with symptomatic CI, following on from the comprehensive CITT studies summarised by Scheiman et al in a Cochrane database publication[ii].


[i] Scheiman M et al. Convergence Insufficiency Treatment Trial – Attention and Reading Trial (CITT-ART): Design and Methods. Vis Dev Rehabil. 2015 Oct; 1(3): 214–228.

[ii] Scheiman M, Gwiazda J, Li T. Non-surgical interventions for convergence insufficiency. Cochrane Database of Systematic Reviews. 2011;(3):CD006768.

How Optometrists Can Help

Case management and duration of treatment will depend on why the child has the convergence insufficiency problem. If it is because they have never refined this ability, then a broader optometric visual therapy program will be required, of which developing convergence skills is but one aspect. In these cases, usually spectacle lenses are not required.

Treatment of acquired convergence insufficiency will require the prescription of spectacles. In some cases, because these lenses reduce the visual demands on the visual system this is all that is needed. In other cases however, visual therapy will also be needed to rebuild and develop the visual stamina and convergence skills. It is important that the glasses are worn in the classroom as well as for all homework, reading, computer, or any prolonged close work tasks.

In an uncomplicated case, vision therapy may take between 4 to 6 in-office visits which are usually spaced one to two weeks apart. For the developmental convergence insufficiency case, a longer period may be required to develop and teach all the required visual skills

Why does my child have a problem

Your child does not have a muscle problem. It's not that they can't turn either eye inwards. Rather they are unable to turn both eyes inwards together, and sustain this position.


Sometimes children are born with these problems or they occur very early in life. However, it's nearly always delayed development or a fatigue problem caused by close work.


One of the reasons for this may be that the child has never refined this ability. With the start of school work and learning to read, this problem becomes more apparent. Another reason may be that the visual system may be tired and allowing one eye to drift out. There is a breakdown in the ability to sustain near alignment of the eyes due to visual fatigue.

  • Difficulty sustaining attention at visually demanding tasks

  • Headaches

  • Occasionally a child will also complain of double vision or the letters moving or running (swirling)

  • Abnormal posture when trying to center on near tasks, including head tilting or holding their work very close

  • Squinting when reading

  • Closing an eye when reading

  • Sore, red or tired eyes

  • Blurred near vision

  • Avoidance of reading

  • Poor comprehension and/or poor reading fluency

  • Holding a book too close when reading or tromboning it back and forth to see words clearly

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