I'm thinking it depends on what you're used to.
Sensory deprivation does seem to help me, but so does an honest days work.

When I get up in the middle of the night for bladder relief (which, sadly, happens with more frequency these days) I don't want to use the Braille technique to find the toilet, nor the sudden shock of lighting the entire room from a state of total darkness. So I have a little night light in the bathroom, which I can see when I rise from the bed. And after I do what is necessary, I fall asleep again.