Experts aren't so sure—and they say the news shouldn't deter anyone from getting tested for coronavirus.

By Claire Gillespie
January 06, 2021
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This week, Hilary Duff shared pictures on Instagram of a fun family Christmas in Boston, with sledding and husband Matthew Koma dressing up as Santa. But it wasn't all good—Duff ended up in the emergency room with an eye infection.

On her Instagram story on January 4, Duff, 33, wrote, "my eye started to look weird… and hurt… A lot… Sooo… took a little trip to the emergency room." The actress believes it's due to "all the Covid tests at work" (she returned to the set of her TV show Younger in October after filming of the seventh season was postponed due to the pandemic), adding, "Cuz you know, 2020, and all."

Credit: Instagram @hilaryduff

The good news is that Duff's eye is fine, and the infection cleared up after antibiotics. But it's definitely got people wondering how you get an eye infection from COVID-19 tests—which are done with a swab in the throat and nose. For starters, current information from the Centers for Disease Control and Prevention (CDC) doesn't list eye infections as a side effect of nasal swab COVID-19 tests.

"A COVID-19 swab is a small, sterile probe that collects mucus," Christopher F. Thompson, MD, an ear, nose, and throat specialist with Providence Mission Hospital in Orange County, California, tells Health. "It is placed along the nasal cavity floor to the nasopharynx (the upper part of the throat, behind the nose). The eye is separated from the nasal cavity by a fibrous layer called the periorbita, as well as bone (lamina papyracea). The tear duct does drain into the nasal cavity, but a swab does not disrupt this tear duct. Therefore, a swab in the nose shouldn't cause an eye infection."

Contamination is always possible, but the test requires you to wash your hands well, both before, during, and after the process. The CDC swab test instructions state that you should apply hand sanitizer (containing at least 60% alcohol), covering all surfaces of your hands and rubbing them together until they feel dry. This step should be repeated twice—after placing the swab in the sterile tube and putting the cap on the tube, and again after disposing of the surplus sample kit items. If these steps are followed, there should be very little chance of contamination, regardless of how many times you get tested. "A COVID-19 test should not cause an eye infection," Dr. Thompson says.

According to the National Eye Institute (NEI), an eye infection—aka, pink eye or conjunctivitis—is most often caused by a virus or bacteria (Duff's use of antibiotics suggests bacterial conjunctivitis, FYI). The NEI adds that eye infections can also be caused by allergies (pet fur or pollen), or other eye irritants (chlorine or makeup).

It should also be noted that some associations have been made between the coronavirus and eye infections. A case study from the University of Alberta, published in the Canadian Journal of Ophthalmology in June, found that conjunctivitis can be a primary symptom of COVID-19. The American Academy of Ophthalmology has also warned that the coronavirus can cause conjunctivitis. However, the CDC doesn't include eye infections on its list of common COVID-19 symptoms. "Red eye isn't a common manifestation of COVID-19, but it has been reported," Kathryn A. Colby, MD, chair of the department of ophthalmology at NYU Langone Health, previously told Health. (Luckily, in Duff's case, she has never reported testing positive for COVID-19).

The bottom line here: If COVID-19 swab tests caused eye infections, we'd know all about it—thousands of people have been getting tested on the regular for several months. Obviously, it's good news that Duff's eye is okay. But if you think you have symptoms of COVID-19, or your work requires you to take frequent tests, don't let this put you off from being evaluated for COVID-19. Keep getting tested, if and when necessary.

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDCWHO, and their local public health department as resources.

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