What happens when you become "mask blind" because your glasses lenses fog up as soon as you get yourself PPE'd up?  Here are some tips to prevent this happening.

1. Soap and water — wash your glasses with soap and water (such as regular washing up liquid), then dry them with a microfibre cloth. Soap reduces surface tension, preventing fog from sticking to the lenses.

2. Shaving foam — apply a thin layer of shaving cream to the inside of your glasses, then gently wipe it off. The residual shaving cream will protect the lenses from misting up.

3. De-misting spray — you can use a commercial de-misting spray that dries clear. But make sure this is compatible with your lens type or existing coatings on your lens. You can buy demisting spray online or from your optometrist.

4. Close the gap  — mould the nose bridge at the top of your surgical mask so that you get a snug fit that prevents that warm breath air from reaching your glasses.  If you make your own cloth mask, add a twist tie  or pipe cleaner to the top seam of your homemade mask and mould that to your nose for the same effect.

5. Damp tissue — a slightly moistened tissue, folded under the top edge of the mask also does the trick.