How to avoid foggy glasses when wearing a face mask
While face masks help us avoid unknowingly transmitting coronavirus, millions of glasses wearers are discovering the nuisance of mask-induced foggy lenses.
What can you do about your fogged-up glasses?
We have compiled tips for lifting the fog from your glasses when you’re wearing a mask, but first let’s go over why your lenses are steaming up in the first place.
Why are my glasses foggy?
Body heat and air flow lead to foggy lenses.
When you’re wearing a face mask, you repeatedly breathe out warm air. This air then can sneak out of the top of your mask and steam up the lenses of your glasses. Of course, this can make it difficult to see.
According to a study published in The Annals of The Royal College of Surgeons of England, a face mask directs much of the exhaled air upward.
The “misting” of lenses happens when warm water vapor from your breath lands on the cooler lenses, producing tiny droplets that scatter light and reduce the lenses’ ability to transmit contrast (when light colors remain light and dark colors remain dark).
“The droplets form because of the inherent surface tension between the water molecules,” the study’s authors said.
SEE RELATED: Coronavirus: How eyes may play a role in its spread
How to avoid foggy glasses
Now that you know why your lenses fog up, let’s review some ways to prevent this fog when you’re wearing glasses and a face mask.
1. Wash the lenses with soapy water
The study from The Annals of The Royal College of Surgeons of England supplies a simple solution to the foggy-lens problem, which it refers to as an “annoying phenomenon.”
Authors of the study recommend that before slipping on a face mask, you should wash your glasses or sunglasses lenses with soapy water and shake off the excess moisture. Then, let your glasses air dry or gently dry the lenses with a clean microfiber cloth.
Using this method, the lenses shouldn’t fog up once you put on the mask and glasses, the study says. Why? Cleaning the lenses with soapy water leaves a thin film that reduces the “inherent surface tension” and prods the water molecules to form a transparent layer.
2. Seal the mask
Keeping your breath in your mask and away from your spectacles keeps your lenses from fogging up.
An easy, inexpensive way to seal your mask to keep your breath from reaching your glasses? Stick a piece of double-sided tape across the bridge of the nose before putting on a mask, advises Dr. Sivaraman Viswanathan, head of the Optometry Department at Sankara Nethralaya.
This will ensure that your mask is well-fitted and will help to prevent the amount of hot air that can reach the lens, adds Viswanathan, who also is a member of All About Vision's editorial advisory board.
3. Adjust your glasses
If your glasses have nose pads, you can tweak the pads so that the frames sit slightly farther from your face.
Be careful, though. Altering the nose pads may slightly change your vision if you wear glasses with progressive lenses or lenses with a strong prescription. If that happens, you might need to hold your head at a different angle to compensate for the vision change.
4. Breathe downward
It might be awkward, but breathing downward can be a quick anti-fog fix. This sends the air away from your glasses.
How do you breathe downward? Hold your upper lip over your lower lip. Then blow air downward, as if you’re playing a flute.
5. Check out anti-fog lenses
This won’t fix your foggy-lens problem right away, but you might consider buying lenses with an anti-fog coating. An anti-fog coating gives you a hassle-free answer to foggy lenses, regardless of whether the obstructed vision is triggered by a face mask or something else.
SHOP FOR ANTI-FOG LENSES: Visit an optical shop near you or an online eyewear retailer to learn more about and to compare anti-fog lens options.
Page published in May 2020
Page updated in May 2021