I tend to get the corner of the eye trickery going on a lot, and I like to believe that it's completely normal.

I've never had a full on hallucination. I don't think. Usually if it's something visual, it's more of a complete blinding affect and my mind goes somewhere completely different and I see a full picture of being somewhere else. Like a vision more than a hallucination. If that makes any sense.

But as for the corner of the eye things, I think those ARE just lighting anomolies and I think a lot of people experience those.