In Scott Alexander's Lot's of People Going Around with Mild Hallucinations All the Time, he shows that several people not currently on LSD still experience mild hallucinations commonly associated with currently taking LSD.
I would like to test to see if I could teach you how to see these mild hallucinations, regardless of experience with psychedelics. Below are 3 tests that should take 1-2 minutes to complete. If you choose to complete 1 or more of these, please comment both failed and successful attempts. Please also comment if you can already see some of these, even if you think it seems obvious.
Test 1: Visual Snow
Description: See the Visual Snow Wiki for a nice visualization on the top-right. I would describe it as "jumpy spiderwebs made out of light", similar in feel to the "black stars" people see when feeling faint (when they get up too quick).
I would say it's NOT the same experience as mental imagination or eye floaters.
[Edit: Honestly I mixed up different phenomena for "visual snow" in my description. Here's the update:
1. Visual Snow - Like a million very tiny dots. Very much like static/white noise in the wiki. More visible in low light conditions or when you're tired. I saw it for the first time this (8/12) morning in low-light conditions.
2. Patterned lines (?) - Like the geometric/kaleidoscopic shape in this picture. Doesn't have to be that consistent or patterned but is better described by "lines" than either of the other two. This is what I meant by "jumpy spiderwebs made out of light" and what I thought visual snow was.
3. Blue-sky Sprites - The picture is a nice animation (can be seen without looking at the blue sky but apparently it's more prominent in that case). Dots and wisps the size of a mm or a little bigger. Maybe 5-100 at a time vs the million in "visual snow". Resembles afterimages and the "black stars" when feeling faint.
4. (Also very possible there's more that I've missed)
]
Test: For 1 minute (click here for a 1 minute timer), close your eyes and try to see the back of your eyelids using your peripheral vision. If a minute elapses with nothing resembling "visual snow", then it's a failure.
If it's a success, then try to see visual snow with your eyes open, again for 1 minute at most.
Test 2: Afterimage Around Objects
Description: It's similar in feel to the image on the right in the afterimage wiki. Similar to seeing a bright light and still seeing it in your vision after you look away.
Test: For 2 minutes max (click here for a 2 minute timer), find a brightly colored object that's against a different flat colored background (a red towel hanging in front of a light tan wall, your face in the mirror in front of a white door, etc), and just stare at the object using your peripheral vision. Don't shift your eyes, just pick a spot and focus on your peripheral vision. If you don't see a colored afterimage of the object around parts of that object, then it's a failure.
Test 3: Breathing Walls
Description: It looks like the static surface you're looking at (floors, walls, ceilings) is shifting, rotating, swirling, "breathing" (sort of dilating back and forth?) even though you know that it's actually still static. Usually more apparent in patterned surfaces than plain colored ones.
Test: For 1 minute, find a larger, textured surface (carpet, pop-corn ceilings, [other examples?]), and stare at it using your peripheral vision. If after a minute of staring you don't see any moving, shifting, etc, then it's a failure.
The short answer is "not like that" and "depends on conditions".
Although I can perceive the snow simply by inclining my attention toward it, most of the time I have difficulty "watching" it because the eyes try to focus on and follow the lights. This doesn't work, I assume because visual snow is a fact of biology and not actually made of photons from the environment. In any case, the movement in the eyes seems to trigger some processing subroutine that renders the noise very briefly smooth and I cannot discern any patterns. I expect this effect is related to (saccadic masking)[https://en.m.wikipedia.org/wiki/Saccadic_masking?wprov=sfla1], which renders us functionally blind for a few milliseconds every time the eye moves.
Under these conditions, and with eyes open, the snow overlay reminds me most of an old TV with the antenna just slightly out of alignment, or maybe a very slightly grainy photograph. If I were to try to simulate this mode on a graphic I would use HSV color space and add just a little random noise on the Value channel, perhaps with some very transparent noise "clouds" to imply local variations in density. (I'm at work now or I would just do so to make it more clear.)
With eyes closed, I see thousands of tiny blue-white blobs on a dark or red background, depending on ambient light levels.
If the mind is sufficiently concentrated that the eyes don't try to focus and follow, I often begin to experience (create?) patterns in the noise. When I was younger, the noise would produce random large blobs of higher density (still made of tiny blobs) that would continuously change position, shape, size, and to a small degree color. Since I began meditating, instead of the blobs I sometimes get a swirling blue pattern that reminds me of water going down a drain at the center of the field of vision.
As for any sort of patterned lines, I'm afraid I can only report strong afterimages from reading on lit screens for long stretches. Nothing like the diffraction-grating-looking awesomeness in that image.