Visors instead of masks
More and more people are turning to a visor instead of a mouth and nose protector. Whether and to what extent plastic visors help to contain the virus can be read in the following article.
Breathe more freely, smile more recognisably, communicate more easily: The advantages of visors as a replacement for the everyday mask seem obvious. But the benefits of plastic constructions as a virus barrier are controversial. While the state of Hesse, for example, expressly permits face shields in its Corona Ordinance, they are not officially considered a mask replacement in Baden-Württemberg. What does science have to say about this?
Do visors help against the spread of the corona virus?
For self-protection, visors seem to be just as suitable as masks. However, aerosols can spread more easily because of the large distances between the visor and the face.
In general, the following applies to the discussion about visors: The data available is relatively thin, and there is as yet no conclusive verdict on this. In an MDR podcast, virologist Alexander Kekulé described visors as "just as good" as fabric masks. According to the Robert Koch Institute (RKI), however, plastic shields are not an equivalent alternative to mouth-nose masks.
Foreigner protection and self protection - who does the visor protect?
It is important in the debate to distinguish between protection from others and self-protection, emphasizes virologist Johannes Knobloch, who heads the Hospital Hygiene Department at the University Medical Center Hamburg-Eppendorf.
In the case of self-protection, it is quite plausible to assume that the benefits of the visor and the mouthguard are in balance: "The visor is ideal for protecting against the classic droplet infection," he says. It serves as spit protection and also protects the mucous membranes of the eyes. That's why in the professional sector, the mouthguard is always extended by safety glasses or visor.
When it comes to protecting others from infection, however, the visor is somewhat inferior to the mouthguard, says Knobloch. An assessment that the RKI also shares: The plastic shields can usually only catch the droplets that land directly on the visor, the institute reports. A textile mouthguard - as long as it fits well - can also prevent the droplets from flowing past on the sides and slow down the breathing air. Aerosols in particular could be better captured by textile coverings, says Knobloch.
Infection possible despite visor
His colleague Kekulé also qualified his statement on the equally good suitability of visor and mask: This only applies if you don't sit in closed rooms with others for very long. Assuming that two people with visors talk to each other for a long time, an infection from such aerosols could well occur. However, it has not yet been conclusively clarified how large the role of aerosols is in the occurrence of infection with sars-CoV-2.
Visors offer a social advantage
Knobloch finds the transparent visors particularly useful in everyday situations in which facial expressions play a role: "Conversations with hearing impaired people are much easier to conduct, for example.
An alternative, not a substitute
And even if the RKI looks at visors skeptically: Whoever is unable to wear a mouthguard for medical or other valid reasons, shows by wearing a visor "that he supports the measures currently taken for the population and thereby wants to make a contribution, perhaps even a minimal one," says the Institute's homepage.