Online Dream Machine won't work for me?

I have tried many times now the online dream machine http://www.netliberty.net/dreamachine.html based on Brion Gysin's original Dream Machine which is supposed to incite natural hallucinations via staring at flickering lights with your eyes closed. I've yet to get any effects at all after repeated attempts, but most people report vivid experiences with ease when using this. Anyone know anything about using this more effectively? Am I not in the right state of mind? Also want to note, I've been on antipsychotics pretty regularly for 12 years now, could the anti-hallucinogenic properties of these be related?