• Posted July 10, 2026

Mild COVID Can Lead To Long-Term Hidden Eye Problems

Doctors are shedding new light on a hidden eye condition that can develop after even a mild case of COVID.

Researchers say a growing number of patients are experiencing severe eye pain, light sensitivity, trouble reading and difficulty focusing months — or even years — after infection.

Yet routine eye exams often appear normal.

"We found that the problems experienced by those affected were not detectable by standard tests," said researcher Neil Lagali, professor of experimental ophthalmology at Linköping University in Sweden. "We had to perform specialized examinations to detect deviations. The puzzle pieces then fell into place, and we found explanations for the symptoms."

For a new study, published July 8 in the journal Nature Communications, his team used high-powered microscopes to compare the eyes of 132 people who had had mild COVID — the majority with lingering eye problems.

They also conducted advanced testing on tear samples.

Among those with eye symptoms, researchers discovered ongoing inflammation and damage to nerves that control multiple eye functions.

They also found some patients' pupils were letting in too much light, while others developed an unusual form of crossed eyes, suggesting problems with eye muscle control.

The symptoms were so severe, 1 in 3 patients reported being on full- or part-time sick leave.

"These people are really struggling in their daily lives. Now we know what's wrong with their eyes, and have several clues as to how COVID-19 may have caused these problems," Lagali said.

The authors hope these findings lead to better diagnosis and effective treatments.

More information

The American Academy of Ophthalmology has more on COVID-19 and eye health.

SOURCE: HealthDay TV, July 10, 2026