When you’re on a commercial flight, you’ve probably noticed that the airplane cabin lights dim during takeoff and landing. This isn’t just to set a mood. There’s a surprising reason behind it: safety.

The risk of an emergency is higher during takeoff and landing. As such, these are the most critical phases of flight. Dimming the lights helps your eyes adjust. If something goes wrong and you need to evacuate, your vision is already accustomed to lower light levels, which makes it easier to find your way out.

Additionally, dimming the lights makes the emergency path lighting and exit signs stand out more. These lights are designed to guide you to safety, and they’re much more visible when the cabin isn’t brightly lit. This way, in the event of an emergency, passengers can quickly and clearly see where to go.

Imagine the lights were bright, and suddenly, there’s an emergency. If you’ve got to quickly move to darker conditions, like those outside at night, your eyes would need precious seconds to adjust. Those seconds could be crucial in an evacuation scenario.

Flight attendants also prepare for possible emergencies during these times. They ensure everything is secure, seats are upright, and tray tables are stowed, all to make sure there’s a clear, unobstructed path if evacuation becomes necessary.

So, next time you’re settling in for takeoff or landing and the airplane cabin lights dim, remember it’s not just about comfort. It’s a well-thought-out safety measure designed to protect you and ensure a swift, safe evacuation if needed.