I have had rainbow halos around street and car headlights since my early twenties. I first noticed it whilst tripping and have yet to determine whether the cause is physical or mental. Looks pretty though.
You may have astigmatism or some other more "mundane" issue there. I see them partially too, but it's astigmatism, because when I put on my glasses they go away. Some do it more than others, but that may be related to the spectrum of the light, which varies quite substantially.
(On that note, here's an old HN post I recall about how to cheaply and easily see light spectrums: https://news.ycombinator.com/item?id=971413 Of course you can't do that with car lights very easily, but you can still check incandescent vs. florescent vs. LED, etc. fairly easily, and perhaps learn to correlate which is which when you see the "rainbows".)
I thought it could be something to do with my eyes but never thought it could be corrected. Looks like I'm due an eye check! Last time was when I was 6 I think..
A lot of that stuff is always there - just think of the hundreds of optical illusions that can be constructed! - but until it's connected with an emotional experience during a trip, the brain doesn't single it out.
The effect that jumped out at me was focusing at a spot on the floor while standing up and turning. It creates the momentary impression of a spiral pattern in my perception. Especially with a dot-like pattern on the floor :)
I've had something similar since at least my teens. At night if I look closely at streetlights, I see what looks to me like a magnetic field around streetlights. I don't think that's what I'm actually seeing, but that's what it looks like.
As mentioned in another message, you may have astigmatism. I get triangular spikes off of relatively point-sources at a consistent angle of about 10 degrees clockwise from vertical from my astigmatism. Your angle will vary, of course.
This could be HPPD[1] or related. There seems to be uncertainty as to if hallucinogens cause some of these effects directly, or if they simply help train the mind to notice what was already there. For instance, is visual snow there already, and hallucinogens simply make one more aware of it and capable of focusing on it (similar to how tinnitus is worse if one focuses on it)?
(On that note, here's an old HN post I recall about how to cheaply and easily see light spectrums: https://news.ycombinator.com/item?id=971413 Of course you can't do that with car lights very easily, but you can still check incandescent vs. florescent vs. LED, etc. fairly easily, and perhaps learn to correlate which is which when you see the "rainbows".)