Distance Learning May Cause Convergence Insufficiency

Laird Harrison

November 16, 2021

NEW ORLEANS — The increased use of digital screens for school during the COVID-19 pandemic may be causing convergence insufficiency in children, researchers say.

Although the long-term implications for current schoolchildren is not clear, convergence insufficiency sometimes persists for a lifetime, said Kammi Gunton, MD, interim chief of pediatric ophthalmology and strabismus at Wills Eye Hospital, in Philadelphia, Pennsylvania.

"It's important, if we use digital technology for education, that we are aware that it might contribute to increased eye symptoms in children," Gunton told Medscape Medical News.

Gunton's colleague, Jordan Hamburger, an MD candidate at Sidney Kimmel Medical College, Philadelphia, presented the finding here at the American Academy of Ophthalmology (AAO) 2021 Annual Meeting.

Convergence insufficiency is an impairment of binocularity. Symptoms include headaches while reading, words that seem to move around the page, blurriness, diplopia, and eye fatigue. It can be treated with exercise, prism glasses, or, rarely, surgery.

"We have some kids who improve with either time or maturity, then we have other patients who suffer from it for their entire lives," Gunton said.

Previous research has linked the use of digital screens to convergence insufficiency, so when many schools shifted to distance learning for the pandemic, Gunton and her colleagues wanted to see whether it would have this effect on the students' eyes.

They surveyed 110 healthy schoolchildren and adolescent students regarding eye symptoms before and after a day of virtual school. The mean age of the participants was 14 years (range, 10–17 years). The participants spent an average of 6.96 hours per day in virtual school. Forty-one percent also attended school in person part time. These students filled out the survey on days when they were in virtual school.

The participants answered questions on the Convergence Insufficiency Symptom Survey (CISS). The survey consists of 15 questions about eye complaints. On each question, the students rated symptoms from 0 to 4, with 4 indicating a severe symptom.

The average sum of the CISS scores rose from 5.17 before school to 9.82 after school, a statistically significant change (P < .001). Sixty-one percent of the participants reported an increase in convergence insufficiency symptoms.

Seventeen percent scored a total of at least 16, which is the threshold score considered suggestive of convergence insufficiency.

The researchers also found that, on average, the more hours each student spent in virtual school, the higher their CISS scores.

This makes sense, because reading requires convergence, Gunton said. The same problem might occur in traditional school if the students were looking at books all day instead of focusing on objects at various distances in their classrooms, such as the teacher or the whiteboard. "So, in the past, if you read a book, maybe you wouldn't read for several hours, but now we're asking children during virtual learning to stay on a device with the camera on," she said.

Previous research has shown that people blink less when reading or using electronic devices, probably because of their increased concentration. This might explain symptoms such as burning and itching. Fifty-three percent of the students reported an increase in asthenopia symptoms.

The researchers would have liked to have compared the students in virtual school to a matched group of students in traditional school. However, almost all students were enrolled in virtual school when the study was conducted, making such a control difficult.

Although previous research has related virtual learning to myopia, as reported by Medscape Medical News, this study did not investigate myopia, and the researchers do not believe that convergence insufficiency causes myopia or vice versa.

Parents can help prevent convergence insufficiency during school by reminding their children to take breaks, Gunton said. She recommends the 20/20/20 rule: After 20 minutes of work that involves looking at objects nearby, students should take a 20-second break and look at something 20 feet away.

"I also think the take-home message is for parents to ask students if they're having symptoms," she said, "and if they hear complaints while kids are on the computers, to have them see an eye doctor and have an evaluation."

Stephen Lipsky, MD, who wasn't involved in the study, said he is seeing more cases of eye strain at Children's Healthcare of Atlanta, in Atlanta, Georgia, where he is a consulting ophthalmologist.

"The study is very valuable in that it shines a light on the fact that these children do have symptoms, such as asthenopia or convergence insufficiency," he told Medscape Medical News. "But I'm optimistic that with a return to more traditional learning, we will return the more traditional incidence of these problems."

Gunton and Lipsky have disclosed no relevant financial relationships.

American Academy of Ophthalmology (AAO) 2021 Annual Meeting: Abstract PA016. Presented November 13, 2021.

Laird Harrison writes about science, health, and culture. His work has appeared in magazines, newspapers, on public radio, and on websites. He is at work on a novel about alternate realities in physics. Harrison teaches writing at the Writers Grotto. Visit him at lairdharrison.com or follow him on Twitter: @LairdH.

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