Not exactly what was asked, but I’ve had allergies all my life and wear masks when mowing the yard. I’ve always struggled with my safety glasses fogging up. The solution I came up with is a woman’s fashion item. They make these small double sided pieces of tape that women use to hold their dress, apparel, . . . to their body. I put one of those in the top of the mask and it seals the top to my face and no more fogging of the glasses. I’ve been using a KN95 mask lately and I can feel the air going out around the side of my face when I exhale instead of up around my nose into my glasses.