A nurse told me flu-like virus can be transmitted through the mouth, nose, ears and the eyes, so a mask of this kind wouldn't do much to prevent transmission. After all, the eyes are internal organs completely exposed to the environment, so they as much prone to infection as the nose and mouth. In addition, masks like this tend to retain bacteria that can cause other kinds of trouble, so people would have to be constantly replacing them with new ones, which again, will not prevent transmission.
When my wife had a doctor appointment earlier this week, I asked her to confirm this with her, and she said it was correct. The doctor said this kind of mask is meant for when the person wearing it wants to prevent infecting other people when they are sick, and not the other way around, so that complements what the nurse said before. The doctor also mentioned that Japan, Sweden and South Korea have refused to submit to social isolation, and infection rates in these countries remain unchanged. I have lived in Japan, and I know how densely populated it is, and if Corona virus infections have not increased there alone, I guess that means social isolation has no effect whatsoever, as it seems in the real world.