I'd suggest that you show him this:
http://en.wikipedia.org/wiki/Psilocybin
http://en.wikipedia.org/wiki/Psilocin
http://en.wikipedia.org/wiki/Mescaline

One more thing, your eyes do go red because of dryness but the blood vessels DO dilate because of this:
http://en.wikipedia.org/wiki/Cannabi...ist_of_effects (see bottom effect) or http://en.wikipedia.org/wiki/Keratoconjunctivitis_sicca