Face shields offer no protection against the coronavirus if an infected person nearby sneezes without a mask on, a study shows, Report says, citing RIA Novosti.
Researchers used computer models to visualize droplets' spread around a face shield ejected by a human sneeze from 3ft (1m) away.
It reveals 'vortex rings' produced by the sneeze carry infectious particles to the face shield in less than a second and stick to the edges of the plastic, the Daily Mail reported.
Researchers say if coronavirus particles' timing coincides with the face shield wearer breathing in, the person can become infected.
Similarly, there is no evidence — and it is 'unlikely' — that face shields are an effective control against aerosol transmission.
A separate scientific paper published in July also found face shields are not protective against COVID-19 — but masks are.
Swiss officials investigated an outbreak of 'several' coronavirus cases at a hotel in a village in the Alps — even though employers took precautions.
Experts revealed only those who wore plastic visors were infected. According to the study, no-one who wore a mask, either alone or in addition to a face shield, caught the coronavirus.
Researchers have previously found shields allow nearly 100 percent of tiny airborne droplets released by coronavirus-infected patients to escape through visors.