Sore and sensitive eyes have been found to be the most significant vision-based indicator of the novel coronavirus, according to a new study conducted by Anglia Ruskin University (ARU) in England.

The new research, published in the journal BMJ Open Ophthalmology, tapped into data from questionnaires among eighty-three patients who were recently diagnosed with the coronavirus, also known as COVID-19.

The team eventually settled on the fact that sore eyes was significantly more common in individuals who had tested positive for the virus, with 16 percent of respondents reporting the issue as one of their symptoms. Only 5 percent admitted that they had dealt with the condition before the study.

Moreover, 18 percent said they suffered from photophobia, or light sensitivity, as one of their symptoms, but this was discovered to be only a 5 percent increase from pre-coronavirus states.

“This is the first study to investigate the various eye symptoms indicative of conjunctivitis in relation to COVID-19, their time frame in relation to other well-known COVID-19 symptoms and their duration,” the study’s lead author Shahina Pardhan, director of the Vision and Eye Research Institute at ARU, said in a news release.

“While it is important that ocular symptoms are included in the list of possible COVID-19 symptoms, we argue that sore eyes should replace ‘conjunctivitis’ as it is important to differentiate from symptoms of other types of infections, such as bacterial infections, which manifest as mucous discharge or gritty eyes. This study is important because it helps us understand more about how COVID-19 can infect the conjunctiva and how this then allows the virus to spread through the body.”

Among all of the respondents, 81 percent reported ocular issues within two weeks of the onset of other coronavirus-related symptoms. Of those patients, 80 percent said that their eye issues lasted two weeks or less.

The most common symptoms were found to be fatigue (90 percent), fever (76 percent), and dry cough (66 percent).

Last month, another vision-based study out of Washington University School of Medicine in St. Louis suggested that human eyes may have the ability to resist infection from the coronavirus.

“SARS-CoV-2 does not replicate at all” in the transparent layer known as the cornea, according to the study, which was published in the journal Cell Reports.

The researchers, however, did not determine whether other tissue in and around the cornea, such as the tear ducts and the conjunctiva, are vulnerable to the virus. 

The U.S. Centers for Disease Control and Prevention has stated that the coronavirus has the potential to enter through the eyes.  

Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek, and Arirang TV. Follow or contact him on LinkedIn.  

Image: Reuters