October 2019

When looking at a near target, such as text on a page (or a phone), the eyes converge so that both are fixating on the object of regard. Convergence Insufficiency, in which the two eyes struggle to maintain fixation together on a near target, is a reasonably common condition in childhood and a cause of double vision, blur at near, and reading difficulty. It has often been treated using vision therapy.

More than 10 years ago the Convergence Insufficiency Treatment Trial (CITT) showed that office-based vision therapy was superior to placebo for treatment of measurable indicators of convergence insufficiency (“near point of convergence” and “positive fusional vergence”). Two follow-up papers from this study were published this week (online pre-publication) in Optometry and Vision Science and show that although these measurable markers of the condition improved with vision therapy, patient reported symptoms (via a patient survey) and, most importantly, reading performance, were not improved by vision therapy any more than by placebo.

The two take-home messages from these trials are:

  1. If you treat convergence insufficiency, use clinical measures, rather than self-reported symptoms, to assess the severity of the condition and the response to treatment; and
  2. if you treat convergence insufficiency, do not claim that it will improve reading skills, because it doesn’t any more than placebo.  

These studies were funded by the National Institutes of Health in the USA, and conducted by academic optometry units across the USA. The study chairperson was Dr Mitchell Scheiman OD PhD, Professor at Pennsylvania College of Optometry and a vision therapist.


CITT-ART Investigator Group . Effect of Vergence/Accommodative Therapy on Reading in Children with Convergence Insufficiency: A Randomized Clinical Trial. Optometry and Vision ScienceOctober 23, 2019.

CITT-ART Investigator Group. Treatment of Symptomatic Convergence Insufficiency in Children Enrolled in the Convergence Insufficiency Treatment Trial–Attention & Reading Trial: A Randomized Clinical Trial. Optometry and Vision ScienceOctober 23, 2019.

This international annual global day of awareness was started in 2000 by Lions Club International, and aims to be a call to action for governments and NGOs, as well as individuals. 

This year the theme is “Vision First”. Worldwide there are more than 250 million people with visual impairment, 36 million of which are blind. More than 75% of these people are suffering avoidable causes of vision loss, and almost 90% of visual impairment is suffered in low and middle income countries.

In Australia, Vision 2020 is focussing on the inequality of health outcomes experienced by people of Aboriginal and Torres Strait Islander descent, and on prevention. We recommend regular eye checks, especially for over-40s, quitting smoking, eye protection for sports and work, regular exercise and following a healthy diet, wearing a hat and sunglasses, and managing diabetes.


World Sight Day Forrest Eye Care