I have a completely uniformed theory about the visual effects of shrooms, including but not limited to the truffle variety. I notice that though I "know" that lines that my eyes may fall on are straight ,(for instance, walls, corners, ceiling) they just do not appear straight. They seem to bend, but the bend is elusive or hard to find because it simply isn't there. If you are still with me, here is my stupid theory. When sober, your eyes look out on the world upon the same horizontal axis. That is, my right eye, looking forward, falls on the wall at the precise height that my left eye does. One can transpose a straight line, across the face from pupil to pupil, directly upon one's field of view. Perhaps when hallucinating this is not so. If ones eye were to look out at a slight vertical angle with reference to the other, it seems that it would be impossible to see a straight line. I mean to say that hallucinating has a kind of effect that they eyes operate without the same degree of unity as in a sober state. Maybe, while hallucinating, the subject can look at another persons left eye with the only his right eye, and the others right eye with only the subject left eye - staring face to face. I have never tried this and have yet to trip after arriving at this mind-f**k. Any comments?