Before we dig into the details, here are a few quick fixes to get rid of that extra moisture on your glasses:
- wet glasses with water, and then lather just a little bit of soap on the lenses (real soap, not the bath cream or stuff like that). The soapy layer should stop fogging;
- place a small folded piece of tissue or paper towel around the bridge of your nose to capture moisture from breathing;
- use tape: fix your mask across the bridge of your nose and across your cheeks. This is the method many doctors use;
- apply a layer of shaving cream and then wipe it off with a napkin -- this can work as a protective layer;
- try adjusting your mask and glasses by pushing the glasses up your nose and tightening the mask by tying it crisscross -- this doesn't always work, but it might help;
- use professional anti-fog spray.
Now, let's look a bit more into why this happens and why these fixes work.
Face masks and glasses can be annoying
It was one of the most debated topics in the ongoing pandemic: face masks. But as the scientific information came in, it became increasingly clear that face masks can substantially reduce viral transmission. The bottom line: masks help.
But if you wear glasses, you've probably noticed a problem: face masks make glasses foggy.
According to the Vision Council of America, 2 in 3 adults wear glasses at least sometimes, and if the mask and glasses don't fit just perfectly, it's impossible to see anything. Unfortunately, physics works to our disadvantage this time.
Why this happens
In 1996, a study analyzed in detail why this happens.
"When a spectacle wearer enters a warm environment after having been in a cooler one, his/her spectacles may ‘mist up’ due to the formation of condensation on the lens surface. Both the physical properties of the spectacle lens and a number of environmental factors determine how long spectacles take to demist," wrote authors Tom Margrain and Chris Owen
Unfortunately in this case, the condensation is brought by warmer air from your nose or mouth, and there's no way to demist so your glasses will constantly be foggy.
So if you want to stop your glasses from being foggy while wearing a face mask, there are two approaches you can use: either stop your breaths from reaching the glasses, or use something to create a de-fogging layer on the lenses. Both ideas can work.
Fixes that work
A 2011 study published in the Annals of the Royal College of Surgeons of England took a look at a very simple way to prevent glasses from fogging. The aptly named study "A simple method to prevent spectacle lenses misting up on wearing a face mask" explains:
"Immediately before wearing a face mask, wash the spectacles with soapy water and shake off the excess. Then, let the spectacles air dry or gently dry off the lenses with a soft tissue before putting them back on. Now the spectacle lenses should not mist up when the face mask is worn."
There you have it -- a scientific, peer-reviewed study showing an easy way to prevent lens fogging by using soap as a surfactant. But it's not the only way. Shaving cream is also a good surfactant and can be used for the same purpose. Of course, there are also professional products on the market.
The other approach is to stop your breath from reaching the glasses. Some doctors use tape to fix the face mask tightly on the face, but that might not be appealing to some people. A more approachable way would be to tie your mask criss-cross to make it tighter.
Alternatively, you can use a small folded piece of tissue to trap the moisture from breathing. You place the tissue snugly around the bridge of your nose so that it doesn't wiggle around. The tissue would trap the moisture, moisture doesn't reach your lenses, problem solved.
Wearing a mask can be uncomfortable at times, and wearing it with glasses can be doubly so. But these are trying times, and this is a pandemic that threatens the entire world. If wearing face masks can prevent disease transmission and save lives, that's definitely something we should consider.