Below is a link to a great article showing how biophotons in the meridians can serve to cause changes in the body. One caveat I would have to it is the underlying presuppositions regarding the metaphysical and evolutionary foundations upon which it is written. Having said that, it gives a whole new meaning to the verse found in Matthew 6:22 -- The lamp of the body is the eye. If therefore your eye is good, your whole body will be full of light. But if your eye is bad, your whole body will be full of darkness. If therefore the light that is in you is darkness, how great is that darkness!