Tulane study: Total darkness during the night
is a key to success of breast cancer therapy.
But it grabbed me when it mentioned melatonin. I take very mild melatonin for sleep, and there is a little light leak into my room at night. I turn toward the wall when I get into bed because I don't like the bit of light from the window.
Even if you don't read the whole thing, consider the possibilities: is it going too far to take precautions on the strength of a lab study? After all, keeping the light out may make us sleep better regardless of any lab studies. And they're not asking us to take some scary new medicine, just to turn off the light.
It might be inexpensive to do something about light coming in around the door.
You might get used to a sleep mask.
If you don't have blackout curtains, would you consider getting them? - Streetlight light and traffic light does come in around "blackout" shades.