Why Do Airplane Windows Have That Tiny Hole?

The little dot in your airplane window is a tiny vent. It works like the ear on your nose when you fly. When the plane goes up, the air outside gets thin and pushes hard against the cabin. This hole lets extra air escape so the pressure stays balanced inside. If it did not have this hole, the glass might crack from too much push. You can see the dot clearly because it is in the middle layer that you look through. It makes sure your ears do not pop too much and keeps the window strong. Next time you fly, check out that small circle near the top of the pane.