Preschoolers take in many sights and experiences throughout the course of a day, and many of them serve to lay the foundation for reading. But those sights can’t be processed quite as accurately if they’re not seeing them clearly — and according to experts, this happens more often than parents are aware.
An estimated 4-to 14% of preschool-aged children have moderate farsightedness (hyperopia) which often goes undiagnosed and untreated. A study funded by the National Eye Institute (NEI) showed that uncorrected farsightedness is associated with “significantly worse” performance on a test of early literacy.
“This study suggests that an untreated vision problem in preschool, in this case one that makes it harder for children to see things up-close, can create literacy deficits that affect grade school readiness,” said Maryann Redford, D.D.S., M.P.H, and program director in Collaborative Clinical Research at NEI in a statement to Newswise.
Impact of hyperopia
In the study, 492 children aged 4-to 5-years old were divided into two groups: those with moderate hyperopia and those with normal vision. Without being made aware of the child’s visual status, an educational assessor administered the Test of Preschool Early Literacy (TOPEL).
Compared to their normal-vision peers, children with uncorrected moderate hyperopia did worse on the exam. Their performance was most affected in the area of print knowledge, which assesses the ability to identify letters and written words.
These differences are meaningful because formal learning often begins in the preschool years, says Marjean Taylor Kulp, O.D., M.S., distinguished professor in the College of Optometry at Ohio State University and lead author of the study.
“In addition,” says Dr. Kulp, “other research exploring the long-term effect of early deficits in literacy has shown them to be associated with future problems in learning to read and write. This makes early detection of these problems important.”
Early literacy skills
To diagnose and get ahead of the problem, preschool children may benefit from an assessment of early literacy skills, says Elise Ciner, O.D., professor at the Pennsylvania College of Optometry at Salus University and co-investigator of the study.
While further research is needed to determine whether correction of moderate hyperopia with glasses can prevent the development of deficits in early literacy skills, Ciner believes that educational interventions for children with early deficits can lead to greater educational achievement in later years.
The symptoms of hyperopia may be difficult to recognize in younger children, who may just think the world looks that way normally. But in general, the symptoms of hyperopia include headaches, eyestrain, squinting, and blurry vision (especially for close objects).