Researchers have measured the effect of letting kids’ vision problems go untreated.

The new study shows that uncorrected farsightedness (hyperopia) in preschool children can lead to significantly worse performance on a test of early literacy.

The study compared 4- and 5-year-old children with uncorrected hyperopia to children with normal vision. It found that children with moderate hyperopia did significantly worse on the Test of Preschool Early Literacy (TOPEL) than their normal-vision peers.

“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 researcher Maryann Redford.

The results revealed significantly worse performance on the TOPEL among children with uncorrected moderate hyperopia, especially those who also had reduced near visual function.

Performance was most affected in the print knowledge domain of the test, which assesses the ability to identify letters and written words.

“These differences are meaningful because formal learning for many children begins in the preschool years,” said researcher Marjean Kulp.

“In addition, 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.

The team concluded that further research was needed to determine whether correction of moderate hyperopia with glasses can prevent the development of deficits in early literacy skills.