A new Canadian study suggests standard vision tests aren't adequately screening children for binocular vision issues. Study authors argue that children with undetected binocular vision issues are at a greater risk of suffering academically, especially on reading tests.
Researchers at Ontario's University of Waterloo compared the vision of just over 120 schoolchildren with their reading scores. Study participants ranged from six to 14 years old.
In their initial vision screenings, three-quarters of the children scored well on the standard visual screening tests. Interestingly, over one-third of these children also scored below average when tested for binocular vision. Unsurprisingly, the children with binocular issues had lower reading scores than children without these issues.
This study proves that even if a patient scores a perfect 20/20 on their visual screening, they could still have an underlying binocular issue. People with binocular issues don't have a problem actually seeing images on a page, but they do have difficulties focusing their eyes while reading a text.
Ophthalmologists often split binocular vision issues into three groups: oculomotor, vergence, and accommodation. All three of these disorders present slightly different symptoms.
An oulomotor issue is characterized by constantly losing one's place while reading a text. People with accommodative problems, however, have trouble with distance vision and focus. Lastly, vergence patients have eyes that can't turn in and out properly while scanning a text.
Since the symptoms of binocular vision aren't widely known or tested for, many children with binocular issues are misdiagnosed. One common misdiagnosis for binocular vision issues is attention-deficit disorder (ADD).
Professors hope this study will encourage optometrists and educators to become more aware of binocular vision issues. They also encourage parents to schedule regular binocular vision screenings, especially if their child has difficulties reading.
Lisa Christian, who teaches optometry at the University of Waterloo, was the lead author on this study. A few other professors involved in this research include Drs. Elizabeth Irving and Patricia Hrynchak.
This study was published in a recent edition of the Journal of Optometry. Study authors entitled this article, "Visual and binocular status in elementary school children with a reading problem."