For those afflicted by bad eyes, being caught without your glasses or contacts can be disorienting. If you need your glasses to see, and you can't find your glasses... well, it's a bit of a catch-22. Fortunately, says Henry Reich for Minute Physics, there's a simple little trick you can use to improve your vision—no special equipment required.
In the video above, Reich explains how if you make a tiny little hole with your fingers it will improve your ability to see everything in that small circle. (It's only an incremental improvement, though, so if your eyesight is really shot it may not do enough to actually be useful.)
But, this is a trick worth holding on to. For Mental Floss, Nick Greene found out that in the event of a sudden apocalypse—zombies or an asteroid impact, say—that leaves you with only the set of contacts in your eyes, those little lenses would last from just one to three months. After that, it's hand telescopes for everyone.