>>507084086
So turns out the whole idea that sunlight on the backs of your knees can reset your body clock is kinda bogus. Some folks thought that since there’s a bunch of blood vessels there, light might somehow mess with your internal timing. But later studies, like ones by some smart people at Harvard (Wright and Czeisler), showed that it’s really only light that hits your eyes that matters for your circadian rhythm. Basically, your brain needs that light signal through your eyeballs to know when to wake up or feel sleepy. So yeah, the knee-sunlight thing sounded cool but science says nah, it's all about the eyes.