How to Stop Safety Glasses Fogging Up
Glasses fog when warm, moist air meets a colder lens. The fixes are a permanent anti-fog coating, airflow around the lens, and a fit that keeps breath from a mask away from the lens.
Why do safety glasses fog?
Condensation forms when the lens is colder than the dew point of the air touching it — moving from a cold store into a warm room, sweating under a hard hat, or breathing up through a mask.
How to keep safety glasses from fogging up
Choose lenses with a permanent hydrophilic anti-fog coating rather than a spray-on treatment; it spreads moisture into a clear film. Vented goggles or frames that sit slightly off the face let moist air escape.
With a respirator or face mask, seal the top of the mask on the nose so breath goes down, and wear the glasses over the mask edge.
Anti-fog models from our range
Anti-fog markings: N and X
Under EN 166, an anti-fog lens is marked N. ANSI/ISEA Z87.1-2020 added an optional X marking for anti-fog. A lens should only carry the mark when it passed the test — ask the supplier for the report.
What to ask a supplier
Is the coating on both sides of the lens? How many wash cycles does it survive? Is there a test report for the model you want? We list our anti-fog models on the anti-fog safety glasses page and supply the test report per model when available.