I don't see what us being able to see has to do with anything. Like what point are you trying to make? That light affects biological processes? Of course it does.
The point I'm trying to make with this is that light affects human biological processes including the brain which, as far as we can tell, causes cognition. If light transmits information through the reception of the eyes, than that means light as processed as information and causes changes in what we are thinking about. Thus light changes how we think.
In the concept of the eyes it works a little differently, but what I'm saying is: Cells emit and absorb light. If this process functions in any way simlar to how the human eyes function, then light is the basis of all human biological functions, including brain functions. The light acts as signal to a cell that tells it how it should react, so basically your thoughts are based on the light signal from one brain cell to another.
Considering you are contacted by about 2500 photons per second per square inch of your body (yahoo answers info, correct me if I'm wrong), it poses the possibility that your thoughts are possibly influenced by external sources.
Then you throw in "the fact" that the human body produces photons within the visible light spectrum that extend beyond the confines of the human body. It proposes the possibility that others can influence your thoughts.
All of this is dependent on the questions that I posed earlier, but as of yet I have not been able to find answer to these questions.
My theory is based on scientific evidence, as in the scientific mechanisms for my theory are supported, and there are people within the scientific community that believe the same thing I do, but there is little evidence that actually confirms that my theory is true.
I would say that the reasons are two-fold.
1. As I stated earlier, it would be extremely difficult to accurately measure the data that would be required to confirm my hypothesis with our current technology.
2. It proposes some serious ethical issues. Think if telepathic abilities were supported by the scientific community. Scientific support that humans have the direct ability to affect how other humans think, would cause huge problems within mainstream society.