Awesome post! A few thoughts. First, it’s “entoptic,” not “entropic.” And the definition of phosphene is still somewhat loose. For a while, the definition covered anything entoptic that was produced by external mechanical or electrical stimulation (like rubbing one’s eyes, transmitting external electrical signals to the visual system, etc.). It did not include things like migraine auras, afterimages, the stuff you constantly see every second of every day (outside of afterimages, etc. Most people don’t notice this stuff, though, and it was never really named by anyone), your retinal vasculature, the white blood cells present in your retinal blood seen in Scheerer’s Phenomenon, etc. Now, there seems to be a really loose use of the term to describe anything entoptic. This seems sloppy to me, personally, although it IS very practical. But take when you see your retinal vasculature, for instance. Is this a phosphene? Or is it you entoptically seeing your retinal vasculature? Is a blue dot seen during meditation a phosphene, or an unidentifiable entoptic phenomenon? The definition is loose largely because not many researchers care about entoptic phenomena as a whole, only about Scheerer’s Phenomenon to help diabetes patients, etc.
The inimitable S. Stratodrive informed me that the phenomenon in which one one sees spiralling, luminescing mosaics and masses of ghostly color when one presses one’s hands into one’s eyes is “an entropic phenomenon called a ‘pressure phosphene’ and it’s a result of stimulating your retinal ganglion cells.” He also shared that it’s sometimes called “prisoner’s cinema” by those in the darkness of jail.
The stimulation of these cells need not be manual: phosphenes can also result from magnetic fields, radiation, drugs, standing too quickly, or other conditions. Amazingly, astronauts report seeing phosphenes, presumably due to the radiation they encounter in space.
This is evidently because the high-energy particle radiation in space, blocked for us by our atmosphere, activates the cells responsible for detecting light; while I initially assumed this meant that, in a sense, we see such radiation (in a beautiful kaleidoscopic way), another author suggests a different explanation:These ionizing radiation-induced free radicals generate chemiluminescent photons from lipid peroxidation, which are absorbed by the photoreceptor chromophores, modify[ing] the rhodopsin molecules (bleaching) and start[ing] the photo-transduction cascade resulting in the perception of phosphene lights.
I’m sure Jack can comment further, but I would note that (1) I think phosphenes are beautiful and, in their demonstration of the lower-order processes of our perceptions, fascinating; (2) I learned the word “psychoplasticity” while reading about this; and (3) the image above is a composite of photographs of lightstick chemicals poured into a toilet; I was searching for representations of phosphenes, which I’d like to see, and it was the best I found.
Also, it is totally unproven that retinal ganglion cells are the source of phosphenes, pressure or otherwise. Take the “chessboard” pattern most people see when they rub their eyes. No one knows what that is, although it almost certainly comes from the visual cortex. There are countless theories regarding the actual processes behind pressure phosphenes, and the retinal ganglion cell one is merely one. And I can basically guarantee you that not all pressure phosphenes are centered around the RGCs. If anything, I think that the Intrinsically Photosensitive Retinal Ganglion Cells (ipRGCs) may be responsible for some entoptic phenomena. If you don’t know about ipRGCs, they are essentially the third basic type of photoreceptor, discovered about 10 years ago. But they have never been demonstrated to take part in the process of vision - only in the regulation of circadian rhythms. Like cones, there are three known types - M1, M2 and M3 cells. All IpRGCS are sensitive to blue light (460nm peak, I believe, although different studies have determined differing figures), and connect both to the Suprachiasmatic Nuclei (SCN), which regulates circadian rhythms, and the Olivary Pretectal Nuclei (OPN), which relates to the pupillary reflex. I have a hunch, though, that certain things we see entoptically stem from direct light stimulation of the ipRGCs, perhaps UV light (although most of this is blocked by the lens), which is not far from the peak spectral sensitivity demonstrated by these cells. But I could be completely wrong.
Also, depending on how you want to define phosphenes, the phenomenon known as “prisoner’s cinema” consists primarily of non-phosphenes. Again, this depends on how you use the word. I think of phosphenes as being mechanical and (external) electrically-stimulated, rather than what you see that comes from other, less apparent stimulation. But phosphenes can totally be used to describe the whole spectrum - but then it is merely a renaming of “entoptic phenomena”. And the phenomenon of prisoner’s cinema is nothing unusual or extraordinary AT ALL - everyone sees that stuff constantly, every second of every day, whether their eyes or opened or closed. It’s just that most people have “tuned it out,” like one tunes out white noise. Pay attention to them. Try to look carefully at everything you see. Paying attention to your afterimages can be very helpful if you want to cultivate this kind of awareness. Stare at a lightbulb for two minutes and then look closely at what you see. Try meditating and pay attention to all the wild crap there is to see. Then you will start to notice it all the time (don’t drive yourself nuts, though hahaha). And yes, it is VERY beautiful. And very, very, VERY significant. I think that entoptic phenomena are actually some of the most spiritually profound elements of existence, but that is another story. They also reveal a great deal regarding the arbitrary nature of perception, color vision, etc (I mean, I guess that’s spiritually profound too, but hey). Many spiritual traditions also place a great deal of emphasis on entoptic phenomena. Many yogis, for instance, have claimed that the appearance of a blue dot (which I did my Master’s Thesis on) is the literal apprehension of your soul. Others also argue that entoptic phenomena correlate very closely to your primary energy chakras, and give you information regarding them. If you see a blue dot, for instance, it is telling you something about your throat chakra (represented by blue) and what it represents (communication, etc.). A white light, of course, is considered by tons of people from all cultures to be divine - the appearance of God or the Higher Self or whatever. And think about it - when you enter a hypnagogic state and begin having mini-dreams, are those entoptic? Are those phosphenes? Are dreams themselves entoptic? When you daydream, are you seeing it entoptically? And since all color vision is invented by the brain, is color technically entoptic? Where is the line? Is there one? How do you define these things? I sure as hell don’t know.
If you haven’t already, I will bet you ten dollars that you will flip your lid if you check out the filmmaker Stan Brakhage. A great deal of his 380 or so completed films consist of nothing but painting on film to create a strictly entoptic experience; it’s quite spectacular. In many films, he also painted on what he filmed to create a more authentic visual experience, since film does not capture the afterimages, phosphenes and other goodies that accompany everything we ever see.
Keep up the interest in entoptic stuff! :)
i’m fallin apart, im barely breathin’
with a broken heart, that’s still beating.
in the pain, i find healing
in your name, life finds meaning.
|—||Had Enough - Lifehouse ft. Christ Daughtry (via youaintseennothinglikemeyet)|