When it comes to traveling flying is the best option and the fastest means of transport in the world. There are certain rules and safety regulations that are being followed by airlines.
Have you ever thought about this strange and weird moment when airplane dim their lights for taking off and landing?
The Cabin Crew gives a lot of instruction before taking off and landing like turning off cell phones, avoiding the use of earphones, tray tables are stowed.
These instructions actually play an important role while flying in the air. These instructions are for passenger’s safety to handle stressful situations just in case anything goes wrong while in the air.
It is also an indication that their flight runway is cleared for takeoff, or they are in the final moment of landing before the plane touches the ground.

In terms of dimming the lights while taking off and landing it happens only because of safety measures taken by the airline to ensure passenger’s eyes adjust into the darkness and ensure they see the gloom floor lights leading anyone to safety along the aisle in the event of a crash or in an emergency evacuation.
If passenger’s eyes are adjusted to the dark anyone will be able to find the floor gloom lights and therefore can leave the aircraft quickly by following the lights. Passengers would have an option to use the overhead lights, which will give enough light for reading and completing crossword, but these lights are of less intensity so that passenger’s eyes are adjusted to it.
While in the air at a high altitude route this is not the reason for dimming the lights, it is only to make passenger sleep.