White light in vision is a symptom of many things, both in medicine and even in meditative practice, and can mean different things (both positive and negative). Now that we know the OP was in a medically induced coma, the light could actually be any number of things, potentially even as a result of the drugs he was given (although, again, we'd need to know what they were exactly and look at any studies or evidence indicating that such a side effect has ever previously occurred, and even then we can't rest our weary minds as we're still on the outskirts of the wasteland of uncertainty).

Like you mentioned, we could probably go back and forth about the topic since there are many tangents to explore, each of them quite interesting but ultimately deviant from the topic at hand.

I appreciate where you're coming from, and rather than hammer away at each other back and forth with tangential reply after reply, let me just end with a thought: Perhaps you are ignoring the mysticism present even within science. What is an electron, truly? What is a wave? What is gravity, really? Magnetism? These are all incredibly "understood" topics, yet their true nature seems to evade our conceptual grasp always, which is why we continue to study them. In essence, there is an essence, and regardless of what you call it, even if you're doped up on some good stuff while you're recovering from a head injury, who can truly argue against the results if someone uses that experience for developing compassion and discipline in their lives. It's something our society desperately needs, regardless of which multi-limbed deity you side with.