New research has shown that deficits in visual function are more frequent in children with developmental dyslexia.

The observational study by researchers from Boston Children’s Hospital, published in Jama Ophthalmology, compared 33 typically developing (TD) school-age children with 29 children with developmental dyslexia (DD). The frequency of deficits in vergence (amplitude, fusional ranges, and facility); accommodation (amplitude, facility, and accuracy); and ocular motor tracking (Developmental Eye Movement test and Visagraph eye tracker) were far more frequent in the DD group compared with the TD group with 23 children in the DD group (79%) and 11 children in the TD group (33%) having deficits in one or more visual functions. Accomodation deficits were more prevalent in the DD group compared with the TD group (55% vs 9%); while in ocular motor tracking, 62% of DD children had scores in the impaired range compared with 15% in the TD group; and vergence deficits occurred in 34% of the DD children and 15% in the TD group

The findings suggest deficits in visual function are far more prevalent in school-aged children with DD than in TD readers, said study authors. “But the possible cause and clinical relevance of these deficits are uncertain. Further study is needed to determine the extent to which treating these deficits can improve visual symptoms and/or reading parameters.”