I won’t turn one of the two lights in my bathroom on at night, not even for a second.
It’s far too bright.
After sundown, I leave all of the lights in or near my bedroom off, or on full dim.
I avoid bright light at night as rigorously as possible.
I do this because it disrupts sleep patterns, or circadian rhythms.
Having a disciplined bedtime routine is just as important as a healthy morning one.