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Physical Distancing First, Face Shields Next

"We label the evidence about eye protection as low certainty, meaning any effects are suggestions."
[It's] not yet clear the relative contribution of eyes, versus nose vs. mouth."
Derek Chu, clinician scientist, McMaster University

"If you happen to encounter the respiratory droplet right next to you, and it lands in your eye, that is a potential risk."
"If we want to protect, for example, the elderly themselves then covering the eyes is an important concept."
Dr.Theresa Tam, Chief Public Health Officer, Canada

"[There's a role for face shields if masks aren't available], but that's something that needs to be discussed on where and when [shields] can be best used."
"I should remind you that masks alone will not protect you. Face shields alone will not protect you from infection."
"[All measures, including physical distancing, remain] really paramount."
Dr.Maria Van Kerkhove, head, Emerging Diseases and Zoonosis Unit, World Health Organization

Students wear face shields and gloves at the “Faik Konica” primary school in Pristina , Kosovo, on June 9, 2020. Schools in Kosovo are gradually reopening after almost three months of restrictions due to the COVID-19 pandemic. ARMEND NIMANI/AFP via Getty Images

"They're far more comfortable to wear, there's no breathing issues with them, they're not uncomfortable on hot summer days."
"They definitely cover the eyes, the nose and the mouth. You're less likely to touch your face, because you've got a shield on."
"The other beautiful aspect of them is that there are no issues with verbal and non-verbal communication. You can see people's faces right through them. The psychological and social benefits are significant."
"I'm not here to tell people what to do. I'm here to help people make informed decisions for themselves. But I think we should at least be open-minded to it."
Dr.Isaac Bogoch, Infectious Diseases specialist, University Health Network,Toronto

University of Iowa researchers produced a study, whose conclusion is that wearing face shields is superior in many ways to wearing face masks to ward off the potential of contamination by the hugely infectious novel coronavirus. Writing in JAMA, the Iowa team suggested that face shields, readily put together with materials sourced from craft and office supply shops could help contain COVID-19 infections.

While simple face masks, layered to filter out most of the tiny virus-sized particles hovering in the air when people cough, sneeze, talk or breathe, face shields, according to the Iowa researchers, may represent a superior option. Soap and water is all that is needed to cleanse shields, the shields can be "reused indefinitely". They wear comfortably, block mouths, noses and eyes from being entered by the virus and "reduce the potential for autoinoculation".

Face shields, visors or goggles may reduce to a significant degree the opportunities for viral infections or transmission, from 15 percent with no eye covering, to six percent, according to another review, published in The Lancet. This was a review commissioned by the World Health Organization with an eye to synthesizing all available evidence on physical distancing, mask-wearing and eye protection.

Most studies were initiated to report on SARS or MERS and not SARS-CoV-2, involving for the most part, health-care settings, leaving the study authors to admit they cannot be "overly certain in the precise quantitative estimates of effects". For the general public, physical distancing of over one metre is "highly effective", face masks protect against infection and provide eye protection; "typically under-considered" they can confer added benefits, even while nothing gives complete protection.

There is evidence the virus is capable of entering the body through mucous membranes, with the inclusion of the mucous membranes on the surface of the eye and inner eye lids. Conjunctivitis (pink eye) has been reported present as a sign of COVID-19. 38 people with COVID-19 were presented in a brief report out of Hubei province in China, where "Ocular abnormalities" consistent with conjunctivitis was found in a third of the patients.

"Although there is a low prevalence of SARS-CoV-2 in tears, it is possible to transmit the virus via the eyes", the researchers wrote in JAMA Ophthalmology. No randomized trial of face shields versus cloth masks have been undertaken, but one study suggested face shields can protect people from inhaling 96 percent of droplets laden with flu following a cough, standing within 18 inches of the cougher.

At the recommended six-feet of physical distancing, the shield blocked inhaled virus by 92 percent, "similar to distancing alone and reinforces the importance of physical distancing in preventing viral respiratory infections."