CNN  — 

It’s a pesky problem: As soon as you strap on your cloth face mask and head out the door, your glasses fog up.

But there’s a simple fix for that, and it’ll only take a minute or two. All you need is soap and water.

This advice comes from the medical journal Annals of the Royal College of Surgeons of England, courtesy of two doctors. And if their defogging trick can work in the emergency room, it can certainly work in the grocery store.

Why fogging happens, and why this solution works

  • Your specs fog up because the mask directs your breath upward instead of in front of you, which is good for preventing disease transmission but bad for anyone with less-than-stellar eyesight.
  • Soap and water act like a cloak that reduces surface tension on the lenses. This magic mix allows the water molecules from your breath to distribute evenly, rather than cluster on your lens in a way that makes it difficult to see.

    1. Always wash your hands with soap and water first

    Remember, scrub for 20 seconds (two rounds of “Happy Birthday”) before you rinse.

    2. Wet your glasses, then lather some soap on the lenses

    There’s no time limit for lens scrubbing, so be gentle and thorough.

    3. Rinse your glasses under warm water

    Don’t leave any soap suds on your lens – if the fog didn’t obstruct your vision, bubbles certainly will. They’re not fun to rinse out of your eyes, either.

    4. Gently dry your glasses with a clean towel or lens cloth

    Avoid using a towel that may scratch your delicate lenses.

    Enjoy your clear specs, and go on your way!

    And now that your glasses are clear, find out about how to wear a face mask.