Use a nose clip
Because the hot air will rise above the mask, you just need to pull the mask up to hug the bridge of your nose. But to fix it, we should use a mask with a nose clip to hug the bridge of your nose more tightly to avoid the mask slipping down when moving vigorously.
This is the easiest way because most medical masks on the market are equipped with this nose clip and are also cheap. The downside is that when you move too vigorously, the mask will slip off, and pulling it too high will block your vision. Wash glasses with soap
This is a method that is widely used by surgeons and has been published in the Journal of the Royal College of Surgeons of England as well as in the American Medical Library (Med Pub), March 2011, proving that this method is quite effective.
The method is extremely simple, you just need to put the glasses in a mixture of soap and water, then shake off the water and let it dry naturally. If you are in a hurry, you can use a soft cloth to gently wipe the glass surface. This method is effective because the water and soap molecules have created a film that prevents the formation of fog on the glass.
The solutions you can use are baby shampoo, hand soap, dishwashing liquid, etc. For glasses with special coatings, you need a doctor's prescription to avoid damage. Use anti-fog spray for nearsighted glasses
There is currently a very convenient anti-fog spray on the market, you just need to spray it and it will create a film that prevents the prevalence of fog on your glasses. Some types are also formulated to suit the function of each type of glasses: swimming goggles, safety glasses, diving masks, etc.
Although simple, you need to choose sprays from reputable, quality brands to avoid damaging the special coating of some types of glasses. Do not use anti-fogging sprays and they will be harmful if they come into contact with your skin and eyes. Fix the mask with sports/medical tape
This is quite effective because the mask will be tight, hug the bridge of your nose and will not fall off easily. But you should be careful to choose medical tape, sports tape, etc. to help sensitive skin. When removing it, you must be gentle because it can easily hurt.
The method is simple, just cut a piece of adult mask 10 - 15cm long, then stick the top edge of the mask to the bridge of your nose, remember to press it tightly. You can also stick it on both ears to minimize the hot air escaping and fogging up your glasses.