London, Dec 9 (IANS): In a fight against the novel Coronavirus, researchers, including one of Indian-origin, have revealed that sore eyes are the most significant vision-based indicator of Covid-19.

"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," said study author Shahina Pardhan from the Anglia Ruskin University (ARU) in the UK.

For the results, published in the BMJ Open Ophthalmology, the research team asked people who had a confirmed Covid-19 diagnosis to complete a questionnaire about their symptoms, and how those compared to before they tested positive.

The study found that sore eyes was significantly more common when the participants had Covid-19, with 16 per cent reporting the issue as one of their symptoms.

Just fiver per cent reported having had the condition beforehand.

While 18 per cent of people reported suffering from photophobia (light sensitivity) as one of their symptoms, this was only a fiver per cent increase from their pre-Covid-19 state.

Of the 83 respondents, 81 per cent reported ocular issues within two weeks of other Covid-19 symptoms. Of those, 80 percent reported their eye problems lasted less than two weeks.

The most common reported symptoms overall were fatigue (suffered by 90 per cent of respondents), a fever (76 per cent) and a dry cough (66 per cent).

"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," the study authors noted.