how to see photons I recently saw a couple of videos, in which you could visualize photons traveling through something (a bottle, for example). So my question is: how does it works? How can we see light if it doesn't reach our eyes? Is there something related to the "wave" aspect of photons?
 A: More mundane than  Brionius' link:   I've created images of lab equipment with the laser beams fully visible via double exposures.  I took one photo of the lab under normal lighting.  Then , in pitch black conditions, I locked the camera shutter open and "walked" a white card along the laser beam paths.
The final image came out pretty good-looking :-) (and sorry, it was actual film & the print was lost years ago).  
A: All we see are photons, and nothing else. But in this context, I think, what you mean is - how can we see the slow moving photons.
Some of the slow moving photons have to scatter and come out of the bottle in order to reach your eyes. So, even though, you do not see the non scattered, still moving photons of the light, by seeing only the scattered photons, you are able to sense the movement.
This way, if someone slows down a single photon, I do not think, that photon can be seen by a human unless it hits the eye.. 
I do not think the slow moving single photon would enable detection by reflecting/deflecting/refracting... any other photons towards us.
