Try soapy water. A British surgeon published a paper in 2011 showing that washing your glasses with soapy water and letting them air dry can help. Soap acts as a surfactant — which stands for surface active agent — and the soapy water leaves behind a thin film that stops the water molecules from forming droplets that lead to fog.
“As a person who wears glasses I found myself affected by this issue when operating,” said Dr. Sheraz Malik, senior clinical fellow at Manchester University Hospitals NHS Foundation Trust and the author of the report. He noted that operating rooms tend to be kept at low temperatures, making the “misting” problem a real issue for surgeons who wear spectacles.
“I haven’t timed it, but the technique reliably works for more than a half-hour when operating,” Dr. Malik said. “Obviously if the face mask is tightly secured on the nose, there is less escape of the moisture toward the glasses and the technique works for longer.”
Try other home remedies. Popular suggestions for treating lenses this way include baby shampoo, toothpaste and shaving cream. (Vinegar is often suggested, but most experts say it doesn’t work.) The main challenge of treating your lenses is adding enough of the substance to stop the fog, but not so much that the coating itself blurs the lens.
Skip the swimmer’s remedy. Swimmers and scuba divers have a regular trick to keep glasses from fogging. They spit into their goggles or masks and rub it around. But given that we’re dealing with a respiratory virus and trying to stop the spread of germs, spitting on your glasses is not advised during a pandemic.
What about commercial anti-fog products?
You can buy commercial anti-fogging wipes and sprays, but it could get expensive. One brand, FogTech Dx, sells on Amazon for $30 for 20 wipes — or about $1.50 per wipe. One treatment is supposed to last for three to five days. The brand is used by food safety and health workers, firefighters and professional skiers and scuba divers who wear protective eye wear, often under extreme conditions.
The wipe contains a combination of absorbent silicone compounds mixed with ethanol. The user wipes the underside of the glasses or goggles, and when the alcohol evaporates, it leaves behind a thin transparent layer that resists fogging. “Our bread and butter is the person who needs to see while protecting their eyes,” said Gene Menzies, founder of MotoSolutions in Fairfield, Calif., which makes FogTech.