Have you ever wondered why there's a tiny hole at the bottom of your airplane window? No, the window is not damaged, and you are not doomed. It's actually a very important safety feature.
The official name for it is a breather hole, and rest assured, every window on that flight has one just like it.
According to an article which originally appeared on TravelandLeisure.com, the purpose of this tiny little hole is to regulate the amount of pressure between the inner and outer window panes, ensuring that the outer window pane bears most of the pressure.
This feature would come in handy in any event that led to added pressure on the window. Only the outer pane, not the inner pane, would give out in an emergency, and you would still be able to breathe.
In addition to this very handy safety measure, the feature also vents the moisture that gets stuck between the window panes, keeping your window fog-free.
So sit back, enjoy the view and sleep a little easier during that in-flight nap knowing that you're a whole lot safer due to that tiny little hole in the window.