the good doctor on: the upside of fog

Blog #46 The upside of fog???

During this pandemic, we have discussed fog, its deleterious effects on optical surfaces. It just so happens that there is an upside to all this fog we have been fighting on our glasses, who knew?

In a recent article in the Economist , researchers in Bethesda, Maryland found that masks protect us from more serious Covid infections by the extra humidity they create. Masks serve as a barrier to airborne pathogens, AND now there is evidence to show that the humidity created behind those masks also helps protect our respiratory tract.

Let’s turn it around, we catch more cold and influenza pathogens in the winter partly due to the fact that cold air holds less moisture and tends to dry out the respiratory tract. This dryness weakens the tract’s defense system. With a mask on, however, the person exhales, the water vapour condenses on the inside of the mask; the person inhales, that moisture is collected by the incoming air and comes back into the respiratory tract. The bronchial tubes are lined with mucous which snares pathogens. Fine hairs, called cilia, push the mucous into the throat. This mucous is then swallowed and stomach acids destroy the pathogenic invaders. Extra moisture helps this clearance system work better.

Findings like these that are hopeful. Humidity is also our friend when looking at dry eyes. The conjunctiva and cornea usually have a layer of mucous that covers them. This layer serves to prevent drying, and it also contains antibodies and enzymes, those helpful parts of our immune system. Humidity is very important for maintaining this mucous layer, so wearing spectacles, increasing air humidity, and increasing mucous production all contribute to keeping the eyes moist and healthy.

Here’s to the benefits of humidity.

Til next week,

the good doctor, Dr. Mark Germain, Burlington Optometrist