Most bathrooms have bright light. Very useful when you're getting ready, but just before bedtime, the bright light gives your body the wrong signals.
When it's dark, your body gets signals that it's bedtime. The bright light in the bathroom does the opposite. The bright light disrupts the signal to go to sleep. Bathroom lamps should actually have a special evening setting. Until that happens, it's best to brush your teeth in the dark, says neuroscientist Russell Foster. It could help you fall asleep faster.
