Hey guys,
I was just doing some concentration practice. I was going through the jhanas, and I didn't notice anything unusual at first, other than that I went through the first jhana a bit faster than I was expecting (or had really intended). Anyway, I shortly moved through the second as well. At which point I opened my eyes, as sometimes it helps me to be able to see my surroundings when in the third jhana. But then something happened that I haven't experienced before (while meditating at least). My field of vision became unfocused and these colors started to appear as what I could only describe as two-dimensional, sparkling, clouds of color. I could still see the objects of my room through the parts of my vision that were unclouded, and these various objects seemed to be twisting and bending.

My questions are: Is this normal? And how should I deal with an experience like this while sitting?

Before someone comments that this might be the A&P, I would like to say that, such experiences are likely not normal, and you should not embroil yourself any further into experiencing such things.

Basically, such altered states of mind, can be detrimental to mental health, especially if you continue to see lights and whatnot.

Who knows what may be next? Seeing green goblins?

Just use your common sense.

It wasn't the A&P, as that does not arise out of concentration practice alone.

If you're doing kasina practice or something involving strong hard concentration, then this kind of thing can happen. MCTB talks about seeing stuff like angels/devils floating through the walls. I've seen deities of light and a huge amount more of very crazy-sounding type stuff. If you have any history of "mental illness" and/or a propensity to experience and/or indulge in these things (which I would argue actually defines what some mental illness is), I would recommend not doing strong concentration practices and to keep your concentration "softer." Strong concentration is not necessary to awaken. Always remember: fear of madness is madness and to let whatever "weird" thing that happened (no matter how bizarre) go and not dwell on it or spend too much time thinking about or analyzing it.

Thank you both, I stopped the meditation when this started to happen, and the distortions went away almost immediately. I do have a strong fear of going insane, but I see myself as a mostly sane person. I think if this happens again I will try to ignore the distortions, because I was a little startled by them, which caused me to focus on them and possibly made them worse.

And about A&P, I'm fairly sure I've past that stage for the most part. But on the other hand I've never been good at determining what stage I'm at.

I have seen numerous stories on the DhO concerning people who claimed to be doing concentration practice but described A&P-like experiences (sometimes asking: "Oh, was that jhana?"). The explanation that comes to mind is that their practice probably isn't nearly as pure with respect to concentration as they think.

Again, I'm fairly certain I've past A&P as I remember the experience explicitly. But thanks for the clarification

I've come to believe that I've been stuck somewhere in a mild Dark Night for quite some time. I keep stopping and starting practice, and I find it hard to sit for more than 5 - 10mins before I start getting restless and have lower back pain. I probably didn't recognize this sooner because of how extreme the Dark Night is usually described as. However, realizing this hopefully moved me a little closer to getting out of the Dark Night. Recently I've been able to sustain meditation for 20 - 30mins again. And while I still get back pain, I have a different feeling towards it I guess.

Anyway, that's my self-diagnosis. It's quite possible that I am wrong. Perhaps I've regressed and have to go through A&P again, I can't be too sure. But I do know that my first A&P experience was nothing at all like what I experienced yesterday with the distortions.

I wonder, do you have migraines with visual auras? That (or something like it) could be an explanation for what you described.

I'm not really sure, I do get fairly frequent headaches, but I've always been told they were sinus related.

Does this look like what you experienced?

http://en.wikipedia.org/wiki/Scintillating_scotoma

Yes, that looks very similar. I may have to ask my doctor about this. I don't remember having a particularly severe headache at the time. Though often times I don't even realize when I have mild ones, because I've gotten used to them.