Get medical tape, tape the mask to the bridge of your nose.

I use this type which have a good seal.

https://www.amazon.co.uk/gp/product/B086LJTJ2V/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

After making sure I have a decent seal across the bridge of my nose, I pull my glasses down slightly so the edge of the mask is slightly underneath.

I found it eliminates most if not all of the fogging.

As a former skier this problem was such a pain in the ass. I finally found goggles that had tiny fans to circulate air. But before that I would position my glasses so they sat maybe a half inch further away from my face. But that held because of the tight fitting goggles. Might be worth trying to add a spacer to your bridge.

As others wrote: Use medical tape or a bandaid over your nose and mask to really seal it.

Or you can use soap. I've heard of this trick elsewhere, but I guess its worth a try. Here is how it should work:

"Soap and Water Help Prevent Fogging

This trick is one that healthcare professionals regularly turn to. All you need for this hack is soapy water (dish soap works best) and a microfiber cloth. Stay away from soaps with lotions in them as they can leave a thick residue, making it even harder to see.
Simply rub both sides of your lenses with a drop of soap, then buff the lenses with a soft microfiber cloth. This effective trick helps prevent your lenses from fogging up as a transparent, thin film of soap acts as a barrier. 

Anti-Fog Wipes and Sprays 

Another option is to purchase wipes and sprays designed to tackle foggy lenses. Read the fine print, as certain anti-fog solutions may not work as well, or may even damage lenses with coatings that minimize glare and fingerprint smudges, for example."


$1

Envo mask works for me.

I just got my hands on a de-fogging spray that works pretty well

I'm in the same situation and almost fell down a flight of steps the other day. It really scared me. The sprays on amazon don't help either neither does the shaving cream recommendations on the articles online. Sorry, I wish I could be of help.

In addition to other comments, you can also head over to your local scuba shop and grab some spray that they use to keep scuba goggles defogged.

Band-aid over the top seam of your mask i prefer 3 for a long day two under the wires and then snack in the middle over them both.

If you're feeling extra wild - or extra long wear go with 5 (if needed) and take it over the sides.

Stick with band-aid brand (i prefer the fabric ones personally for long wear) their adhesive seems better long term, also not nearly as painful. If your face can handle it using a moisturizer to get off the adhesive makes it gentler if it's really stuck on there.

I've also purchased anti-fog solution (rain-x, & somthing from Sam's club) and neither worked at all.

Good luck!

My mom bought Tommy Copper masks and she says they’re great. She gave one to my husband (they both wear glasses) and he said that even wearing it all day at work it was comfortable and no fog or issues with it

Better sealing make work best, like KN95s, but are expensive. Tape or a band air for surgical mask is the next best option. I’d have to find the name of it, but my eye doctors office sells a spray that helps prevent defogging very well

Get better masks eg ffp2 or 3 which will also make you safer :)

Can't remember where I saw it, but somebody wrote that bandaids below the eyes helps.