I think I know exactly what you mean, and you described it better than I ever have. I have a really hard time explaining what I think about it well, so bear with me while I try and wrestle this into language.
Just taking a low dose of DMT (or lsd, or mushrooms) and staring readily manifests this for me while still in this reality. Eye contact with others, and in mirrors, seems to do it even better (and interestingly eye contact activates areas of the right hemisphere). For me it is a feature that accompanies a shift in consciousness, but under certain circumstances this feature is more noticeable than others.
With practice I realized that its possible to enter mental/visual states similar to (usually) lower doses of dmt through relaxed staring (or eye contact and/or mirrors, especially), and this visual phenomena you mention is a major feature of it for me. I'm reminded of how Terence recalled a friends (I think Dennis?) theory that DMT is actually somehow involved in staring deeply into things.
Anyways, its like you stare and relax yourself, and then your focus shifts to encompassing the entirety of our field of vision; as if it's starting to all get processed at once instead of there being a specific focal point, and the rest being merely peripheral data. My friend has remarked that this may be related to how autistic savants can process so much visual information simultaneously... For example, immediately knowing the number of dots on a screen the instant they glance at it. Alan Snyder actually did tests on this in normal individuals to see if he could get a similar affect, and it involved inhibiting the dominance of the left hemisphere using TMS, thereby increasing right hemisphere functions. Their guesses of the number of dots then became more accurate, and he's done many similar experiments since.
Back to the experience of it (sober or otherwise).... When I relax I can sort of coax it to go deeper, to the point where everything I'm seeing just becomes this seamless, vibrating sea of energy, which can get very trancey and go a number of places. I've watched myself disappear when staring at my reflection in the mirror, stone sober, through doing this; all I'll be perceiving is the vibrating sea of energy. A mental shift accompanies it that is not unlike DMT at all really, although its more like dmt + harmalas (taking melatonin also seems to bring this on more readily).
Its almost as if, in addition to processing visual reality more fully/directly, you start seeing beyond the surfaces of things, and your consciousness begins to register the underlying quantum energy that makes it all up.
Sometimes, when it happens sober, everything can appear to be completely alien and new, like you're seeing the world around you from an aliens perspective for the first time...This actually used to happen to me as a kid, and it freaked me the hell out to be honest. But its really just like a more direct or full way of processing the energy around us, it seems...although "experiencing" would be a better word here than "processing", I think, since it's more like instead of processing, you are simply by-passing your ordinary mode of processing and tapping your awareness directly into the raw data coming in.
I think this actually relates perfectly to a major difference in left and right brain processing that Iain McGilchrist and countless other researchers have thoroughly documented, generally showing how one side prefers a narrow or zoomed-in take on things, and the other a much more expansive or all-encompassing approach.
Anyways, I agree that it does seem to heavily translate to the hyperspace experience, but I think I've already talked way too much and already sound crazy enough to people. I think its indicative of a kind of parallel processing inherent to that mode of being, which adds to the already multi-dimensional nature of the experience. I'm reminded of the experiences some here have had that involved 360 degree vision while in hyperspace...
<Ringworm>hehehe, it's all fun and games till someone loses an "I"