It may be useful to anyone.
When I go to the toilet at night, I only turn on the lights so that no one is awakened. Due to the coloring of the retinal pigment when exposed to it light, leaving the toilet, I lose for a while the ability to see in a poorly illuminated room => difficult to get to bed.
I solved this problem by closing one eye when entering the toilet. Thus, one eye becomes illuminated and the other remains adapted to the darkness.