I was on a flight a while back and the stewardess asked me to raise my window blind on landing for “Safety reasons”. She didn’t go into any more detail than that, and I didn’t have the presence of mind to enquire further. So, what’s the straight dope? Why do you need to open your windows on take off and landing? Cheers.
So if there is an emergency, they can look out the window and see if it’s safe to evacuate on that side.
Additionally if there’s been an electrical failure, and it’s daylight, the additional illumination will aid in evacuation or any other activities.
It also helps rescue workers see what’s happening inside the cabin.
The new Boeing 787 Dreamliner has electronically dimmed windows, which I assume are automatically “opened” for take off & landings. Eventually all airliners will probably have them.