Not completely, but it's pretty unlikely it helps. First of all, no one will probably sneeze (or actually cough, because that's the frequent symptom) in your fa

Not completely, but it's pretty unlikely it helps. First of all, no one will probably sneeze (or actually cough, because that's the frequent symptom) in your face directly. If it's not 'in your face', just pretty close, then a lot of the droplets will be too small for the simple surgical mask to filter out. Especially as it leaves a lot of gaps around your nose and mouth. Not to talk about your eyes, where you can get infected just as easily. (Yes, you could wear protective glasses too.) But... if almost everyone wears these in public places, which actually just became compulsory in Czech that should give pretty good protection to everyone (by filtering the emission of the asymptomatic infected). And if we think about this use case, then actually it makes no point telling people that it won't protect them because if they think it will they are more likely to wear it.