T extilmasken in this country are still new and unfamiliar to many or even strange. And many finally want a little normalcy and a little lightheartedness back. Couldn’t transparent face visors be a good compromise?
The short answer: yes and no. For the long answer, we spoke to a doctor and manufacturer of such visors. They explain to us how much the visors bring and what you have to consider when using them.
How is a face visor constructed?
Such a visor is very simple: “It consists of a headband with a flexible band for the head, and the actual visor, a transparent film that is usually made of PET,” describes Dominik Wilming from the Vechta against Corona initiative, the face visors against Covid19 produced. PET is the same material that is used, for example, in returnable bottles. With some models, the foil lies against the forehead, with others there is an extra arch between the head and the foil so that you can carry it more comfortably. The film does not lie on the bottom or on the side, but is open so that the air can flow along there.
When is a face visor useful?
“There is a particular need for such visors, especially in kindergartens and schools, but also in nursing,” explains Wilming. The textile masks currently on offer are particularly a hindrance in areas where you speak a lot and loudly (e.g. at school) or where facial expressions and personal contact are important. Even in people with shortness of breath, the physical and psychological barrier can make the problem worse. This is one of the reasons why the demand for such visors is increasing enormously, in the hope that they can offer a compromise between infection protection and a free face. This is practical, but only works to a limited extent.
What does a face visor do?
“A clear advantage of the visors is that the eyes and thus potential entry points are protected from the virus,” explains Dr. Lutz Graumann from Sports Medicine Rosenheim. It can also stop any coarse droplets that you or someone else releases into the air when you sneeze, cough, or speak. But: “With every cough, around 3000 droplets are ejected at a speed of 90 km / h, while sneezing there are even 100,000 droplets at 160 km / h”, describes Graumann. It is very likely that some of the droplets will simply be pushed past the film and then enter the environment unhindered.
Face visors do not protect against aerosols!
Both experts, doctor and manufacturer, agree that the visor does not help against so-called aerosol transmission. Aerosols are droplets that are so small that you can hardly see them and do not immediately fall to the ground, but “stay” in the air. There is increasing evidence that this is a relevant transmission route for Covid19. Air with aerosols can flow past the visor unhindered. “Some visors get wider towards the bottom and are shaped like a kind of funnel, which could make transmission via the breath even more likely,” warns Wilming.
Does a visor replace a mask?
A visor is therefore very likely to protect your own eyes and, to a lesser extent, perhaps also the environment. However, this effect is not great enough to replace a mouth and nose protection, even the handmade ones probably hold off significantly more droplets than the non-fitting visor. For this reason and also because the effectiveness of non-certified visors has hardly been researched, you cannot meet the mask requirement with face visors in most federal states. However, there are a few exceptions and regional differences.
What is definitely allowed, however, is a combination of both. This gives you external protection through mouth and nose protection and self-protection through the barrier for large droplets and eye protection. “In medical areas where a lot of aerosols circulate, a combination, or a mask and protective goggles, is recommended,” says Graumann.
What do you have to consider when buying a face visor?
If you are looking to buy a visor to protect your eyes and keep out coarse droplets, there are a few things to consider. The two experts have these 5 tips:
- Harmless material: “Especially with products from 3D printers, you should be careful that the material is harmless and robust. PLA, for example, is harmless, but a bit brittle,” says the manufacturer. Visors from the so-called injection molding, on the other hand, usually consist of harmless and resistant PET.
- Proper care and disinfection: One advantage of the visors is that they are easy to clean. “It is particularly important that a soft cloth is used that does not scratch the material,” warns Wilming. To disinfect you can use all commercially available agents that are labeled as “virucidal” in any form. “Only chlorine and acetone, such as those found in nail polish remover, should be avoided because they attack the material.” Be careful not to inhale the fumes from it when you put on the visor.
- A smooth surface: if the visor is scratched, visible or invisible grooves can appear. “On the one hand, they can impair the view, but above all, they are much more difficult to disinfect,” emphasizes Wilming. So always be careful and thorough when cleaning.
- Correct use: Visors protect against infection, among other things, because they make it difficult to touch your face. At least as long as they are properly seated and used. “But if you put your face more than usual with the unfamiliar visor or neglect other hygiene measures out of a supposed sense of security, it makes it worse than better,” warns Graumann.
- The wearing comfort: You can theoretically wear face visors for many hours as long as you clean them every now and then. “The headband in particular should have a certain width to sit comfortably and firmly,” advises Wilming. Applications such as foam or textile can make the headband more comfortable, but are more difficult to clean from the corona virus.