Originally Posted By: haertig
Those tighteners/stiffeners/whatever-you-call-them are useful for those of us who wear glasses, to prevent fogging.


The mask is for preventing a person from spreading the virus via aerosol. If the glasses get fogged it is a sign that the mask is not worn properly. Good masks allow to adjust the metal strip on the nose bridge tight enough to prevent fogging.
_________________________
If it isnīt broken, it doesnīt have enough features yet.