My psycology textbook says that shining light on the back of your knees can cure jetlag, based on the studies of someone named Cambell or something, but the tests haven't been recreated.

Does anybody know if this is true?

Whe u get dependent result in science that seems totally unrelated to the independent variable, u must take a closer look before formulating a theory.

in areas above the arctic circle, people expirience sun-withdrawl, and applying light to the backs of their knees reduces the symptoms.

We appear to have some sort of light-sensitive structures in our legs.
http://www.gi.alaska.edu/ScienceForum/ASF13/1377.html

http://www.mercola.com/1998/archive/light_on_knees.htm


although there is also evidence that there is no effect of this treatment:
http://www.mercola.com/2002/aug/7/knee_light.htm


right now it looks like there is more pro evidence than con evidence, so I'd bet there is something to it. Our skin does produce Vit. D when hit by natural light, so there is some sort of phot-sensitivity built into our bodies outside of our eyes.

How does it cure jet-lag?!

I have never once heard of that as a cure for jetlag.

I would assume the effect on jet-lag would be to help stimulate the body to re-set it's internal clock faster, thus adjusting you to the new time zone faster.

However, given that much of the symptoms of jet-lag are dehydration-related, I wouldn't expect this treatment to have more than a partial effect.