It’s hard to succeed in school if you can’t see the blackboard or struggle to read your assignments easily. Imagine being a young student with poor vision and then being given glasses enabling you to see. It makes a world of difference.

Students who received eyeglasses through a school-based program not only improved their reading and math scores, those students who were struggling the most also showed the greatest academic improvement because of their new specs, the researchers reported.

Students given glasses showed improvements essentially equivalent to two to four months of additional education.

In the largest study of its kind, the eyesight of more than 64,000 students was tested over the course of five years as part of Vision for Baltimore, a partnership of Johns Hopkins schools of Education and Medicine, Baltimore City Public Schools, the Baltimore City Health Department, the eyewear brand Warby Parker and the national nonprofit, Vison to Learn. More than 8,000 pairs of glasses were distributed as a result of the eye exams.

That alone is an amazing feat — but something more was also going on. From 2016 to 2019, researchers from Johns Hopkins conducted a randomized clinical trial analyzing the academic work of 2,304 students from third to seventh grade who received the screenings, eye examinations and eyeglasses. The team reviewed their scores on standardized reading and math tests, measuring the impact of their improved vision over one and two years.

The results were eye-opening. Reading scores increased significantly after one year for students who got glasses, compared with students who received their glasses later. Math performance in elementary students also improved. Even more striking academic gains were seen among girls, special education students and those students who previously had been among the lowest-performing.

Students given glasses showed improvements that were essentially equivalent to two to four months of additional education when compared to students with eyesight problems who did not receive glasses. Although these academic improvements were not sustained over two years, the researchers believe this might be the result of students wearing their glasses less, losing or breaking them.

“This study, grounded in thorough and rigorous research, has proven our most fundamental assumption in launching Vision for Baltimore six years ago — that providing kids glasses in their schools will significantly improve academic success,” Ron Daniel, the President of Johns Hopkins, said in a statement.

“This is how you close gaps,” added the study’s lead author, Amanda J. Neitzel, deputy director of evidence research at the Johns Hopkins Center for Research and Reform in Education. And there’s more good news — the Vision program will continue offering additional Baltimore students the chance to see a brighter academic future.

The study is published in JAMA Opthalmology.