Why is it required for airplane window shades to be open during take off and landing?

Answer 1

This is in case we have to evacuate the plane if there is fire or malfunction and the emergency lighting on the plane does not work, if everyone's shade is down, it would be total darkness. Flight attendants have 90 seconds to evacuate the airplane. Most accidents happen during take off and landing.
No one would like evacuating in the dark.
Hope this helps

Answer 2

i dont know i think so the flight attendents can see but i really dont know