Speaker 1: Hey, you welcome to Stuff to Blow your Mind. My
Speaker 1: name is Robert Lamb and I'm Joe McCormick. And it's Saturday,
Speaker 1: which means we're going on down into the old vault
Speaker 1: to pull out a classic episode of the show for you.
Speaker 1: This one is from last year. This one is from
Speaker 1: March thirty first, twenty twenty two, and it is the
Speaker 1: Three Pupil Die Part two. This is the follow up
Speaker 1: to the episode that aired last Saturday about about strange
Speaker 1: pupils and irises in myth, legend and reality. Welcome to
Speaker 1: Stuff to Blow Your Mind, a production of iHeartRadio. Hey,
Speaker 1: welcome to Stuff to Blow your Mind. My name is
Speaker 1: Robert Lamb and I'm Joe McCormick. In our last episode,
Speaker 1: we discussed a common but enthralling literary motif in Irish mythology,
Speaker 1: the triple and the sevenfold eye, three or seven pupils,
Speaker 1: three or seven irises found in the eyes of beautiful heroes,
Speaker 1: divine seers, destructive monsters. We also discussed the structure and
Speaker 1: functionality of the human eye and the rare instances in
Speaker 1: which we actually see double pupils in human eyes. In
Speaker 1: this episode, we're going to explore more curious eyes from
Speaker 1: the natural world, as well as more accounts of marvelous
Speaker 1: eyes from ancient history and literature. But first a pop
Speaker 1: culture update. At the end of last episode we were talking,
Speaker 1: I spoke briefly about some double eyes that I remembered
Speaker 1: from some movies, album covers, etc. Well, our good producer
Speaker 1: Seth provided us with two additional examples of double eyes
Speaker 1: and popular culture that we didn't think of last time.
Speaker 1: Number one, the double irises and pupils of Aminet in
Speaker 1: twenty seventeens. The Mummy. This is the Tom Cruise Mummy film.
Speaker 1: Oh boy, did not see it, but I think this
Speaker 1: is like the the titular Mummy, or at least one
Speaker 1: of them. I think she is the Mummy in this film.
Speaker 1: I'm okay, I haven't seen this one, not even on
Speaker 1: an airplane, but I'm not opposed to it. I mean,
Speaker 1: I've seen a lot of crummy mummy movies over the years,
Speaker 1: and usually there's something interesting in them. Yeah, at least
Speaker 1: sometimes you get an Arnold Foslou or something. Yeah. And
Speaker 1: then the second example Seth brings up is the album
Speaker 1: cover to Bubba by Haitian Canadian musician k Trenada featuring
Speaker 1: the artist with otherworldly blue eyes that have double pupils,
Speaker 1: double irises. I listened to a track from this album
Speaker 1: while we were working on notes. It was good. I
Speaker 1: haven't had a chance yet, but I do love the
Speaker 1: album cover. It's pretty great now. One of the sources
Speaker 1: that we mentioned in the last episode was the Evil
Speaker 1: Eye in early Irish literature and law. This was published
Speaker 1: in Celtica twenty four back in two thousand and three,
Speaker 1: and this was by Jacqueline Borsch and the author of
Speaker 1: Fergus Kelly is also cited on this paper because there's
Speaker 1: like a part one in a part two, but I
Speaker 1: believe we're we dealt with material from part one. Celtica,
Speaker 1: the journal this is in is a scholarly journal for
Speaker 1: Celtic studies out of the Dublin Institute for Advanced Studies.
Speaker 1: So most of this deals of course with Irish law,
Speaker 1: Irish traditions, Irish mythology, and despite the popularity of this
Speaker 1: motif of the multiple pupils, multiple irises within the Irish tradition,
Speaker 1: we also encounter discussions of this sort of thing in
Speaker 1: other traditions as well, and shares a few of these
Speaker 1: The first one comes to us from A Plenty of
Speaker 1: The Elder and the Natural History. Plenty discusses individuals in
Speaker 1: Africa said to possess quote, the power of fascination with
Speaker 1: the eyes and can even kill those on whom they
Speaker 1: fix their gaze for any length of time, more especially
Speaker 1: if their look denotes anger. Now that's you're pretty basic
Speaker 1: evil eye scenario right there. You encounter variations of this
Speaker 1: throughout the world, based on the fact that, yes, you
Speaker 1: can shoot somebody a really terrible look and you can
Speaker 1: almost feel it. Of course, going back into the ancient world,
Speaker 1: the belief was often that it was more than you know,
Speaker 1: giving somebody the stink eye produced more than just a
Speaker 1: bad feeling, that it could literally curse them or cause
Speaker 1: them magical harm. Yes. But the neat thing here where
Speaker 1: it ties into what we're talking about in these episodes
Speaker 1: is Plenty goes on to connect this to multiple pupils quote.
Speaker 1: A still more remarkable circumstance is the fact that these
Speaker 1: persons have two pupils in each eye. Apollo Nides says
Speaker 1: that there are certain females of this description in Scythia
Speaker 1: who are known as the Bitha and Philarchus states that
Speaker 1: a tribe of the theebe in Pontus, and many other
Speaker 1: persons as well, have a double pupil in one eye
Speaker 1: and in the other the figure of a horse. Double
Speaker 1: pupil in one eye, the other the figure of a horse. Now,
Speaker 1: with passages of this kind, we're often faced with the
Speaker 1: question is this based on some distorted or exaggerated retelling
Speaker 1: of something that somebody actually saw, or is it just
Speaker 1: pure creative imagination or you know, tall tales, And it's
Speaker 1: always interesting to wonder about the former, But ancient accounts
Speaker 1: like Plenties are clearly full of the ladder, especially when
Speaker 1: telling stories about peoples who live in far away parts
Speaker 1: of the globe. You know, this section that we're quoting
Speaker 1: from plenty is from I can't remember what it's called.
Speaker 1: There's like one of his books is all about the
Speaker 1: nations of the world, and it's just all these weird
Speaker 1: stories of like here's a people who live somewhere far away,
Speaker 1: and here's this strange thing they do or something that
Speaker 1: they wear that would be fascinating to my readers. Like
Speaker 1: there's one part where he talks about a tribe of
Speaker 1: people somewhere who do not have heads and instead have
Speaker 1: eyes in their breasts. So it need not be the
Speaker 1: case that Plenty is necessarily here repeating a misunderstood or
Speaker 1: exaggerated story about somebody who actually had something like polychoria
Speaker 1: or some other unusual condition of the pupils. But of
Speaker 1: course it is always possible. Yeah, it does make you wonder,
Speaker 1: you know, to what extent would there be, like, you know,
Speaker 1: some account of an individual with this rare condition, some
Speaker 1: memory of this rare condition, and then it gets folded
Speaker 1: into some of these traditions and beliefs at one point
Speaker 1: or another in their long lives. Yes, though of course
Speaker 1: it could again just be something somebody made up, like
Speaker 1: the people who don't have heads and have eyes in
Speaker 1: their breasts, right right, Like, we can dream up individuals
Speaker 1: with like four arms, and it's pretty interesting and we
Speaker 1: can draw all sorts of meaning from that, but it
Speaker 1: doesn't mean that people with four arms ever actually existed,
Speaker 1: you know, that there's any actual biological basis on which
Speaker 1: that was based. Though. I do think it's really interesting
Speaker 1: that he doesn't just say, Okay, they've got two pupils
Speaker 1: in each eye, but that they've got two pupils in
Speaker 1: one eye and in the other eye a horse. Yeah,
Speaker 1: And like the first place my mind went was, Okay,
Speaker 1: is it actually shaped like a horse a distortion that
Speaker 1: is roughly horse shaped? Or is it? Does it mean
Speaker 1: that this is like some sort of telephone game, you know,
Speaker 1: translation game version of a horizontal pupil like one finds
Speaker 1: in the eyeble horse. That's interesting, and that'll tie into
Speaker 1: a scientific paper we're going to talk about in a bit.
Speaker 1: I found an editor's footnote in the Bostock translation of Plenty,
Speaker 1: which notes, quote, some of the commentators have supposed that
Speaker 1: Plenty or Phi larcis from whom he borrows, because remember,
Speaker 1: this isn't an original observation of Plenties, He's like copying
Speaker 1: this from some other writing of this person named phi Larcus,
Speaker 1: but Philarcus from whom he borrows. Whether they were misled
Speaker 1: by the ambiguity of the Greek term eCos, which signifies
Speaker 1: either a horse or a tremulous motion of the eye.
Speaker 1: But even admitting this to be the case, the wonder
Speaker 1: is scarcely diminished, for we have the double pupil in
Speaker 1: one eye, while this supposed tremulous motion is confined to
Speaker 1: the other. So so if Fostuck is correct there, it's
Speaker 1: that this word had had a double meaning, and one
Speaker 1: of them was like a you know, a quivering of
Speaker 1: the eye. I guess I would assume that's like when
Speaker 1: somebody's eye is twitching. But yeah, you wonder, well, why
Speaker 1: why is it just that the other eye is twitching
Speaker 1: when when the first eye has two pupils in it,
Speaker 1: that's also strange, maybe not as strange as a horse.
Speaker 1: I was. I was looking for answers on this as well,
Speaker 1: and I ran across a nineteen eighteen paper titled of
Speaker 1: the Papula duplex and Other Tokens of an Evil Eye
Speaker 1: in the Light of Ophthalmology by Walton Brooks McDaniel, And
Speaker 1: according to Brooks, here one doctor Kirby Flower Smith, a
Speaker 1: professor of Latin and at John Hopkins University, who had
Speaker 1: I looked VI had died in nineteen eighteen, interpreted the
Speaker 1: Plenty passage as having some sort of connection to the
Speaker 1: idea that the affliction of the eye was caused by
Speaker 1: quote a horse shaped demon, horsehead masked demon. Yeah. McDaniel
Speaker 1: also begins to discuss the the idea that if you know,
Speaker 1: if you look into another eye, you know certainly with
Speaker 1: the right lighting and so forth, you look into another
Speaker 1: person's eye, you can see your own reflection. And so
Speaker 1: McDaniel mentions that in some traditions that individual you see
Speaker 1: in the eye is interpreted, you know, not as yourself,
Speaker 1: but as the signifier of the soul, and that there
Speaker 1: are even some traditions where if the individual looks in
Speaker 1: some way inverted, that is because of witchcraft. And in
Speaker 1: this this this is one of those weird situations where
Speaker 1: then McDaniel mentioned something else that leads me back to
Speaker 1: a source that I'm very familiar with, and yet I
Speaker 1: totally blinked on this particular detail, or or maybe I'd
Speaker 1: never read this one particular tale, but he ends up
Speaker 1: referring back to Strange Tales from a Chinese Studio by
Speaker 1: Poosh song Ling. That's a show, favorite, folks. Should we
Speaker 1: do we have a Strange Sales from a Chinese studio? Buzzer?
Speaker 1: I doubt we do, but at any rate, it's it's
Speaker 1: it's a book that I really enjoy. This is a
Speaker 1: Ching Dynasty collection of stories that Pous song Ling collected
Speaker 1: and retells, and you know there's a lot that's that's
Speaker 1: lost in translation. Out of Mandarin. But but there's still
Speaker 1: remarkable fun, sometimes funny, and sometimes it's just very strange. Uh.
Speaker 1: Sometimes it's it's you know, it's all about what they
Speaker 1: would have meant to the people who read them. But
Speaker 1: they're a lot of fun. There's a Penguin edition of
Speaker 1: it translation that I've I read again and again over
Speaker 1: the years, and yet I completely blanked on this one story.
Speaker 1: It's called Talking Pupils. I think maybe the reason that
Speaker 1: I haven't read this one recently is sometimes i'll read
Speaker 1: these to my son and I'll sort of glance at them,
Speaker 1: and if it looks like there's something that might be
Speaker 1: scandalous in it, or you know, a little dirty, then
Speaker 1: I'll skip over the tale. There aren't many, but occasionally
Speaker 1: there's one like that. So anyway, this story Talking Pupils
Speaker 1: concerns the tale of one Feng Dong quote, a gentleman
Speaker 1: of considerable accomplishments while at the same time having a
Speaker 1: reputation as an unprincipled libertine. Oh yeah, so clearly that's
Speaker 1: why I might have skipped over this in recent years. Anyway,
Speaker 1: So Fang was this is how the story goes. Fang
Speaker 1: is strolling the countryside and he happens on a fine
Speaker 1: carriage on the road. One of the female attendants to
Speaker 1: the carriage is quite fetching, so he moves in for
Speaker 1: a closer look. But as he does so, he's able
Speaker 1: to peek between the curtains of the carriage itself and
Speaker 1: he sees a beautiful young woman within, and he's captivated.
Speaker 1: The female attendant is having none of this, though, and
Speaker 1: she verbally shames him, you know, calls him a you know,
Speaker 1: a weirdo and a snooper. And not only does she
Speaker 1: verbally shame him, she reaches down grabs him dust out
Speaker 1: of the road and throws it in Fang's face. Oh,
Speaker 1: dirty fighter. Yeah, but you know, he had it coming.
Speaker 1: He was up to no good and he gets punished
Speaker 1: for it. So he's he's initially he's trying to get
Speaker 1: the dust out of his eyes. The carriage carries on.
Speaker 1: When he is able to see again, you know, struggling,
Speaker 1: the carriage is completely done. It's you know, it's vanished
Speaker 1: around the bend or whatever. So he has heads on home,
Speaker 1: but his eyes continue to bother him, so he seeks
Speaker 1: some help. A friend looks into his eyes, and this
Speaker 1: friend says, yeah, there's a visible film over each of
Speaker 1: your eyeballs, and meanwhile, tears won't stop flowing. In time,
Speaker 1: the film thickens and a spiral what is described as
Speaker 1: a spiral shaped protuberance begins growing from his right eye,
Speaker 1: resisting all manner of treatment. Eventually he's completely blind, and
Speaker 1: you know he's he's distraught over this. But he hears
Speaker 1: about a Buddhist sutra known as the Sutra of Light,
Speaker 1: and it's said to be able to heal eye ailments
Speaker 1: or ailments of this sort. So he gets a side
Speaker 1: friend to read it to him, and he learns it
Speaker 1: by heart, and he recites it over and over again,
Speaker 1: and after a while it gives him solace. You know,
Speaker 1: he feels a little better. His side is not back.
Speaker 1: But then one day he begins to hear voices, two voices,
Speaker 1: one from each of his eyeballs. Oh, I love this.
Speaker 1: The eyeballs are talking, both of them. Well, as it
Speaker 1: turns out, not the eyeballs but things within the eyeballs.
Speaker 1: There's one voice within each eyeball, and they start talking
Speaker 1: to each other, and they're talking about how dark it
Speaker 1: is in their homes and how they'd really like to
Speaker 1: just get outside and go for a stroll. And then
Speaker 1: so pusong Ling says quote, then he felt a slight
Speaker 1: irritation in both nostrils, as if two little creatures were
Speaker 1: wriggling down his nose. After a while, he felt the
Speaker 1: creatures return and make their way back up his nostrils
Speaker 1: and into the eye sockets. Again, this is anatomically correct because,
Speaker 1: as we know, the tear ducks that drain tears away
Speaker 1: from the eyes drain into the nasal cavity, which is
Speaker 1: why your nose when you cry. Oh very good. So
Speaker 1: what does Feing do at this point, Well, he gets
Speaker 1: his wife to take him to the old garden, and
Speaker 1: he has her observe him in the garden to see
Speaker 1: if anything like this happens again. Maybe the garden will
Speaker 1: coax whatever it is out of his eyeballs. And this
Speaker 1: is what happens. Quote. It was not long before she
Speaker 1: saw two little mannekins, neither of them any larger than
Speaker 1: a bean, emerged from his nose and fly buzzing out
Speaker 1: of the door. They were soon well out of sight,
Speaker 1: but we're back again in next to no time, flying
Speaker 1: together up onto his face and in at his nostrils.
Speaker 1: Like a pair of homing bees or ants. So is
Speaker 1: he getting relief when they fly away? I don't think so. No. Oh,
Speaker 1: it's just it happens, and he doesn't know what this
Speaker 1: is about, so it keeps happening. It happens again each
Speaker 1: day for three days, and finally one of the voices
Speaker 1: complains that the tunnel that they're using to get out
Speaker 1: of the eyeball is a bit round about and there's
Speaker 1: got to be a better way. It's time that they
Speaker 1: make some sort of proper doorway. So I'm going to
Speaker 1: read the rest of this year that it really gets
Speaker 1: to the juicy part. I'm just I'm filled with dread.
Speaker 1: It's not a good idea when the tenants in your
Speaker 1: eyeballs decided to start renovating on their own. Yeah, so
Speaker 1: that is how it goes. The wall on my side
Speaker 1: is very thick, replied the right eye. It won't be easy.
Speaker 1: I'll try to make an opening on my side, said
Speaker 1: the left eye. Then we can share my door. Presently,
Speaker 1: Fang thought he felt a scratching and a splitting in
Speaker 1: his left eye socket, and an instant later he could
Speaker 1: see he could see everything around him with absolute clarity.
Speaker 1: Beside himself with a delight. He promptly informed his wife,
Speaker 1: who inspected his eyes afresh and found that in the
Speaker 1: left eye a minute aperture had appeared in the film,
Speaker 1: a hole no larger than a cracked peppercorn, through which
Speaker 1: gleamed the black globe of a pupil. By the next morning,
Speaker 1: the film in the left eye had disappeared altogether. But
Speaker 1: the strangest thing of all was that, on careful inspection,
Speaker 1: there were now two pupils visible in that eye, and
Speaker 1: the right eye was still obscured by its spiral shaped growth. Apparently,
Speaker 1: both of the two eye mannequins his talking pupils had
Speaker 1: now taken up residence in the left eye. So although
Speaker 1: Fang was still blind in one eye, he could see
Speaker 1: better with his one good eye than he had ever
Speaker 1: done with two. From that day fourth, he was a
Speaker 1: great deal more circumspect in his behavior and acquired unimpeccable
Speaker 1: reputation in the district. Okay, so no more creeping on
Speaker 1: ladies and carriages. Right, he learned his lesson, He was
Speaker 1: punished for his creepy behavior, and now he's back and
Speaker 1: ready to be a good citizen with one eye that
Speaker 1: can see better than two, right, because two pupils. Now
Speaker 1: that this again is from the Penguin Classics edition. It's
Speaker 1: a John Minford translation, and this was super interesting as well.
Speaker 1: Minford shares this in the notes pupils. The traditional Chinese
Speaker 1: expression for pupil, tong wren, means literally man in the
Speaker 1: pupil from the reflection of oneself that one sees in
Speaker 1: the eye of another. Wow. Yeah, that was that was
Speaker 1: really that. I was really impressed by that. And I
Speaker 1: was talking to my wife about it because I was
Speaker 1: looking around a little bit after this and I saw
Speaker 1: an article about photography and about being able to zoom
Speaker 1: in on the eye of an individual in a modern
Speaker 1: photograph and see the reflection potentially of the photographer and
Speaker 1: oh yeah, because of the high resolution, I guess, yeah, yeah.
Speaker 1: And I was asking my wife about this, and she
Speaker 1: pointed out that one thing that photographers can do is
Speaker 1: you can pull up, say a headshot that another photographer
Speaker 1: is done. You can zoom in on the eye and
Speaker 1: you can see what their lighting setup is. So I
Speaker 1: was impressed by that as well. Oh, I'm impressed. That's
Speaker 1: a real James Bond level trick. I do not know
Speaker 1: what to make of the spiral growth though I looked
Speaker 1: around briefly on that and I was not able to
Speaker 1: find any answers that seemed fencing. I have no expertise
Speaker 1: on spiral growths from eyes. All right, I want to
Speaker 1: go back to Borsch for just a minute here, because
Speaker 1: she has a couple of other examples that she brings up.
Speaker 1: One apparently tolomeos Chinos. This would have been a figure
Speaker 1: from the late first early second century. CE once described
Speaker 1: a beautiful woman as being quote with a double pupil. Okay,
Speaker 1: And in the last episode we talked about some legends
Speaker 1: in which a character with multiple pupils this was assumed
Speaker 1: to be a marker of beauty. Right, So this is
Speaker 1: interesting because it seems to suggest that this is not
Speaker 1: just isolated within Irish literary traditions, that perhaps somewhere else
Speaker 1: in the world there was this idea that double pupil
Speaker 1: equals beauty. And I mean, who am I to say
Speaker 1: it's not beautiful? You know, it's not like you look
Speaker 1: at images of actual double pupil situations and you're not
Speaker 1: hortified by them or anything, no more so than if
Speaker 1: you look at a super close up of any human
Speaker 1: Eyeball also mentions that ovid portrays a woman with double
Speaker 1: pupils having the evil eye at one point, so tying
Speaker 1: back into the evil eye tradition. But anyway, Bors concludes
Speaker 1: quote to conclude this section, Both angry eyes and eyes
Speaker 1: with multiple pupils have been connected with the concept of
Speaker 1: the evil eye, there is no strict identity between the phenomena.
Speaker 1: Multiple pupils can also be a sign of beauty, sharp sight,
Speaker 1: and clairvoyance. Okay, so we're not really converging on a
Speaker 1: unity of theme here. If you're in an Irish legend
Speaker 1: or myth and you have a character with multiple pupils
Speaker 1: in one eye, it seems they could either be somebody
Speaker 1: who has a lot of insight, somebody who can see
Speaker 1: very far away, somebody who can see the future, somebody
Speaker 1: who is beautiful, or somebody who is monstrous or can
Speaker 1: do curses. And there is this idea too that it's
Speaker 1: it's part of like the supernatural body, that when you
Speaker 1: have some sort of a demigod figure, it's the human body.
Speaker 1: It's almost like it mutates with the divinity within it
Speaker 1: like the human The normal human body cannot contain this
Speaker 1: level of power and therefore, extra things are going to happen,
Speaker 1: you know, extra pupils, extra fingers, that sort of thing.
Speaker 1: And this ties directly into another example I found, and
Speaker 1: this one comes from Chinese traditions as well. This is
Speaker 1: from the nineteen sixty seven book Chinese Civilization and Bureaucracy,
Speaker 1: Variations on a Theme by Hungarian born French senologist Eten
Speaker 1: Balahs working with working from another source as well, Essay
Speaker 1: on the Extinction of the Soul by Faun Shin, a
Speaker 1: Chinese philosopher and writer who lived four fifty through five
Speaker 1: fifteen CE. The subject here, as far as eyes are concerned,
Speaker 1: is one of the legendary sage rulers of antiquity in China.
Speaker 1: This would concern a time during the third millennium BC.
Speaker 1: And so the structure of this paper seems to concern
Speaker 1: like questions and answers. And so first we have this question.
Speaker 1: The body of the sage is similar to the body
Speaker 1: of ordinary men. Yet there is a difference by which
Speaker 1: the sage is distinguished from ordinary men. From this, it
Speaker 1: can be inferred that body and soul are different. Answer
Speaker 1: not at all. Pure gold glitters and unwashed gold does
Speaker 1: not pure gold. That glitters surely cannot be made of
Speaker 1: the same unglittering material as that of unwashed gold. How
Speaker 1: much less, then, can the soul of a sage be
Speaker 1: lodged in a vessel such as the ordinary man. Nor
Speaker 1: would it be possible for the soul of an ordinary
Speaker 1: man to dwell in the body of a sage. Therefore,
Speaker 1: fengg Sum is depicted as having eyebrows of eight colors,
Speaker 1: and zong Huo's eyes with double pupils, signon as having
Speaker 1: the face of a dragon, and tie how the mouth
Speaker 1: of a horse, all of which are outward bodily signs
Speaker 1: of their exceptional nature. All the seven openings were found
Speaker 1: in the heart of pie Con. The gall bladder of
Speaker 1: poe U was as big as a fist, which shows
Speaker 1: that their inner organs were unusual. Thus we know that
Speaker 1: certain parts of the bodies of sages are quite out
Speaker 1: of the ordinary, and that sages are not only superior
Speaker 1: to ordinary human beings, but also surpass all other creatures
Speaker 1: in bodily form. That's just science. I love this passage
Speaker 1: so much. I mean, I love that it's basically an
Speaker 1: autopsy of supernatural sages, of determining how they're they're but
Speaker 1: like you can imagine this scene in a movie. Oh yeah,
Speaker 1: this is beautiful, the gall bladder as big as a fist,
Speaker 1: showing that the inner organs are unusual. This is great,
Speaker 1: and you know, and this is this is not a
Speaker 1: totally unique view of the body of the holy person
Speaker 1: or the saint. I mean, you know, there are tons
Speaker 1: of traditions all around the world, including like the idea
Speaker 1: that certain types of saints or holy people, because of
Speaker 1: their spiritual nature, their bodies would be found to be say, incorruptible,
Speaker 1: like they don't rot the way most spoties do. Yeah. So,
Speaker 1: but Balais adds some notes on this and points out
Speaker 1: that the legends about the eyebrows of eight colors and
Speaker 1: the eyes with double pupils He's come from Mahan times
Speaker 1: and are contained in a number of different works. So
Speaker 1: yet another example of of of exceptional eyes in the
Speaker 1: bodies of exceptional you know, heroic mythic individuals. Now, in
Speaker 1: the last episode, we talked a bit about human eye
Speaker 1: anatomy and some medical literature on polychoria, or the condition
Speaker 1: of having multiple pupils within the same eye. But I
Speaker 1: thought in this episode it would be a good idea
Speaker 1: to turn to pupils of the animal kingdom more broadly,
Speaker 1: because there's a lot we can learn about the function
Speaker 1: of pupils by looking at the pupils of non human animals.
Speaker 1: That's right. I mean, just consider the vast diversity we
Speaker 1: have in the animal world, and I mean even just
Speaker 1: dealing with the vertebrate world, it's pretty remarkable, not even
Speaker 1: getting into compound eyes of flies and so forth. But
Speaker 1: consider humans. We have round pupils. House cats have vertical slits,
Speaker 1: Tigers have round pupils, Goats and horses horizontal. Dolphins have crescents,
Speaker 1: cuttlefish have w shaped pupils, some frogs have heart shaped pupils,
Speaker 1: and geckos have these sort of what looked like pinholes
Speaker 1: arranged in a vertical line. I always love a good
Speaker 1: crocodile pupil. Oh, yes, tend to be rather vertical. Yeah,
Speaker 1: it's and it's also it's a window into the crocodile soul.
Speaker 1: But seeing all this different diversity does raise some questions
Speaker 1: because you think, okay, well, you know, the bodies of
Speaker 1: animals are shaped by their environment. You know, that's what
Speaker 1: evolution does. It tends to give you the equipment that
Speaker 1: best helps you do whatever you need to do within
Speaker 1: your ecological niche. So why do different animals have different pupils?
Speaker 1: How to differently shaped or sized pupils help an animal
Speaker 1: adapt to how it's supposed to survive in the world. Yeah.
Speaker 1: According to Martin Banks, the vision scientist at the University
Speaker 1: of California that cited in a twenty fifteen NPR story,
Speaker 1: eye shapes of the animal world hint at differences in
Speaker 1: our lifestyles. Land animals of sufficient height tend to have
Speaker 1: round pupils. Thus you have big cats that have round pupils.
Speaker 1: Meanwhile your small house cat cat has vertical pupils. Verticals
Speaker 1: are more the domain, it seems, of smaller ambush predators,
Speaker 1: giving them an excellent ability at judging distances, of which,
Speaker 1: of course, is going to be super important when you're
Speaker 1: pouncing out of the shadows and trying to capture like
Speaker 1: a small rodent or your owner's foot. Horizontal pupils, on
Speaker 1: the other hand, are widely under stood as a means
Speaker 1: of keeping a wider swath of the surroundings in sight
Speaker 1: while you're grazing, and an expanded field of view. So
Speaker 1: you can think of this as the panoramic potential prey
Speaker 1: view of the world, right, So I was actually looking
Speaker 1: into this. The paper that Banks is connected with is
Speaker 1: one that was published in twenty fifteen in Science Advances,
Speaker 1: and it's by Martin Banks, William Sprague, urg And Schmall,
Speaker 1: Jared Parnell, and Gordon Love and it's called why do
Speaker 1: animal eyes have pupils of different shapes? And what you
Speaker 1: say is correct. They looked into this question and they found, yeah,
Speaker 1: there are some very strong correlations between how an animal
Speaker 1: survives and what shape its pupils are, at least among
Speaker 1: land vertebrates. And so you tend to have, like you're saying,
Speaker 1: horizontal pupils if you are a herbivore, whereas ambush predators
Speaker 1: predators that sit around and wait for their prey, they
Speaker 1: tend to have vertical slits, especially if they're active of
Speaker 1: it in both daytime and nighttime. And meanwhile, active predators,
Speaker 1: predators that hunt and chase down their prey instead of
Speaker 1: sitting and waiting, they are more likely to have round
Speaker 1: or circular pupils. And this is not a coincidence. The
Speaker 1: author has found some pretty good reasons why the pupils
Speaker 1: would be allotted in these ways. So first of all,
Speaker 1: you would have to wonder how does it work this
Speaker 1: lay way, Like why would vertical pupils be useful if
Speaker 1: you are an ambush predator, especially as you were saying,
Speaker 1: an ambush predator of low height, because height matters. So
Speaker 1: if you're an active predator chasing down prey, you likely
Speaker 1: have round pupils, or if you're an ambush predator that
Speaker 1: is taller, you probably have round pupils vertical slits of
Speaker 1: what you're really likely to see if you're a sit
Speaker 1: and wait, jump out predator and you're close to the ground.
Speaker 1: So I want to read a section from this paper,
Speaker 1: and there's a couple bits of terminology. To understand the
Speaker 1: quote I'm about to read, it'll use the term stereopsis.
Speaker 1: Stereopsis is depth perception that is created by comparing the
Speaker 1: difference between what is seen by two different eyes focusing
Speaker 1: on the same image. So we use stereopsis to judge
Speaker 1: depth when we look at an image by the brain says, okay,
Speaker 1: we've got two different data points of the eyes, and
Speaker 1: it compares them together and gives you this three D
Speaker 1: image with depth. But then the other term is defocus blur,
Speaker 1: This refers to the blurriness and objects that are either
Speaker 1: close or farther away, closer or farther away than you're focusing.
Speaker 1: So the authors of this paper right quote, vertically elongated
Speaker 1: pupils create astigmatic depth of field, such that images of
Speaker 1: vertical contours nearer or farther than the distance to which
Speaker 1: the eyes focused are sharp, whereas images of horizontal contours
Speaker 1: at different distances are blurred. This is advantageous for ambush
Speaker 1: predators to use stereopsis to estimate distance says of vertical contours,
Speaker 1: and defocus blur to estimate distances of horizontal contours. So
Speaker 1: rob if you'll scroll down a bit in the notes here,
Speaker 1: I attached a picture that they put in the paper
Speaker 1: to simulate what it looks like to a creature that's
Speaker 1: gazing out at the world with vertical slit pupils, and
Speaker 1: it's a very interesting So they've got a picture with
Speaker 1: a toy bird sitting on the ground, presumably a foot
Speaker 1: or two ahead of where the camera is positioned, and
Speaker 1: then there's some objects in the foreground in in the background,
Speaker 1: and what you'll notice about this picture is that the
Speaker 1: bird is very much in tight focus, but then for
Speaker 1: objects around it there is there is an uneven amount
Speaker 1: of blurriness in the vertical and horizontal directions. So like
Speaker 1: there's a plant stalk that's poking right up in the
Speaker 1: foreground and its shape is fairly in focus when you're
Speaker 1: looking at it height wise, you know, like the stalk
Speaker 1: is sort of sort of blurry but sort of in focus.
Speaker 1: But things in the horizontal direction, like the top of
Speaker 1: the pot that the plant is sitting in, are very blurry.
Speaker 1: And apparently it allows these animals to use both the stereopsis,
Speaker 1: the comparing the two different eyes if the animal has
Speaker 1: two front facing eyes, and the way that images are
Speaker 1: blurred when they're at different levels of distance from the
Speaker 1: object in focus to judge depth very well. So you
Speaker 1: can really nail that bird when you jump. So sorry
Speaker 1: if that was a little complicated, but it took me
Speaker 1: while to understand. I was trying to figure out, like
Speaker 1: why the vertical slits actually help with the hunting. But yeah,
Speaker 1: I think it makes sense if you especially if you
Speaker 1: look up the picture, you can say like, oh, okay,
Speaker 1: this is yeah, this is for an animal that is
Speaker 1: precisely trying to target a jump at something. Yeah, and
Speaker 1: you've got one shot pulling it off. But there was
Speaker 1: another thing noted in this pain that I thought was
Speaker 1: really interesting, and this was actually just in the introduction,
Speaker 1: but it was about advantages of slit shaped pupils over
Speaker 1: round ones in general. So we were just talking about
Speaker 1: vertical pupils for a load of the ground ambush predators.
Speaker 1: But slit pupils in general can be advantageous because they
Speaker 1: allow for much greater changes in the area of the
Speaker 1: pupil and thus greater variation in the light conditions they
Speaker 1: can adapt to. So you've got a human pupil. To
Speaker 1: constrict a round human pupil like ours, you need that
Speaker 1: ring shaped sphincter muscle that we talked about at length
Speaker 1: in the last episode. But to close a slit pupil,
Speaker 1: it uses two muscles that close the sides of the
Speaker 1: slit together. And as a result of these morphological differences,
Speaker 1: there is a different amount that you can increase or
Speaker 1: decrease the area of the pupil and the amount of
Speaker 1: light that it can pull in. So, to read from
Speaker 1: the paper quote, the vertical at pupils of the domestic
Speaker 1: cat and gecko undergo area changes of one hundred and
Speaker 1: thirty five and three hundredfold, respectively, whereas human circular pupil
Speaker 1: changes by about fifteenfold. Yeah, species that are active in
Speaker 1: night and day need to dilate sufficiently under dim conditions
Speaker 1: while constricting enough to prevent dazzle in daylight. So a
Speaker 1: slit pupil provides the required dynamic range. So this is
Speaker 1: why a slit pupil is good. It's great for high
Speaker 1: dynamic range for an eye that works great in both
Speaker 1: bright daylight and in pitch dark. And you know, I
Speaker 1: can't help but think with smaller predators as well. I mean,
Speaker 1: these are generally going to be creatures that are not
Speaker 1: only predator but prey as well. So it's not like
Speaker 1: they can just hold up, you know, all day. I mean,
Speaker 1: they may try to hold up all day, but they
Speaker 1: might need to play the survival game during daylight as well,
Speaker 1: assuming they're not actively hunting during the day as well
Speaker 1: of course, right right, So, yes, a slit pupil is
Speaker 1: great for being highly adaptable to whatever the light situation is,
Speaker 1: But the directional orientation of the slit depends more on
Speaker 1: your ecological niche like you were talking about earlier. So again, yeah,
Speaker 1: the grazing herbivores, like horses, they will have horizontal slits
Speaker 1: to help them keep a panoramic view of the environment
Speaker 1: and watch for movement or predators approaching. But another interesting
Speaker 1: finding of the authors here, these pupil orientations for herbivores
Speaker 1: only work if the animal keeps the pupil parallel to
Speaker 1: the horizon, and grazing herbivores actually spend much of their
Speaker 1: time with their heads bent down to the ground eating grass.
Speaker 1: So what gives there? Well, the researchers looked into this
Speaker 1: and they found that, in fact, when horses bind down
Speaker 1: to graze, they rotate their eyes within the sockets to
Speaker 1: keep the pupils parallel to the horizon. And Martin Banks
Speaker 1: in that NPR article he gives a quote pointing out
Speaker 1: that this is weird because the eyes have to rotate
Speaker 1: in opposite directions, you know, think about the eyes on
Speaker 1: opposite side. So yeah, and apparently they couldn't find any
Speaker 1: references to anybody ever writing about this before, which is
Speaker 1: funny given how much time people spend around horses. But yeah,
Speaker 1: so that's what horses do when they've been down to
Speaker 1: the grass. Their eyes swivel in the sockets to maintain
Speaker 1: the pupil slit as parallel to the horizon. Wow, this
Speaker 1: is another one of the I don't know, we've we've
Speaker 1: talked about this before, and you know, imagining alien life
Speaker 1: forms and so forth, but also getting into just ideas
Speaker 1: of consciousness, like how much of our our understanding of
Speaker 1: ourselves in the world seems to come down to how
Speaker 1: we view the world and how we focus attention um
Speaker 1: and yet to try and put yourself in the mindset
Speaker 1: of a mind that is that perceives the world in
Speaker 1: this manner that you know, that that has eyes that
Speaker 1: are always focused on the horizon in order to get
Speaker 1: this panoramic view of all the potential threats that could
Speaker 1: be interfered with they're feeding one lass. Funny note that
Speaker 1: was in that NPR coverage of this paper was about
Speaker 1: depictions of dinosaurs in Jurassic World and other movies. So
Speaker 1: you know, you've got this some kind of giga predator dinosaur.
Speaker 1: It's just like the ultimate what do they call it
Speaker 1: in Jurassic World. It was like the Killer Rex or
Speaker 1: so this is the this is the Hannibal electro one, Yeah,
Speaker 1: Kilamus maximus, yeah, something like that. Yeah. Well, they talk
Speaker 1: about the temptation to depict predators like this with vertical
Speaker 1: slits for eyes, because I think we correctly detect that
Speaker 1: as a predatory trait. You look at a crocodile's eyes,
Speaker 1: it's got these creepy vertical slits, and that makes sense
Speaker 1: because a crocodile is an ambush predator that operates low
Speaker 1: to the ground. But they say, actually this, you know,
Speaker 1: the Kilamus maximus dinosaur is an active predator and it's
Speaker 1: very tall, so it would probably have round pupils like ours.
Speaker 1: And the funny thing is, you can't even use the
Speaker 1: frog excuse, like oftentimes that is used to excuse sort
Speaker 1: of stuck in the mud depictions of dinosaurs in the
Speaker 1: Durassic Park Traffic Jurassic World movies. They'll say, well, you
Speaker 1: have to remember they also used frog DNA, So the
Speaker 1: fact that they don't have feathers that has to do
Speaker 1: with the frog DNA. But it was the frog DNA,
Speaker 1: then perhaps they would all have heart shaped pupils depending
Speaker 1: on the type of frogs that were used. Right, Yeah,
Speaker 1: And that brings us back to the next thing, which is,
Speaker 1: so we were talking about the orientations of slit shaped
Speaker 1: pupils versus round pupils in terrestrial vertebrates. But when you
Speaker 1: start looking at the eyes there are the pupils of
Speaker 1: animals that live in the water. You starts even weirder
Speaker 1: shapes in dolphins and cuttlefish and all kinds of things
Speaker 1: have these strangely shaped pupils. Yeah. The cuttlefish pupil especially
Speaker 1: is very fascinating to look at. Definitely look up a
Speaker 1: picture of it if you're not picturing it right now.
Speaker 1: It looks like this WAVYW. It looks kind of like,
Speaker 1: you know, the face on the Pringles can. Is that
Speaker 1: mister Pringles, Doctor Pringles, I can't remember, doctor Pringles. Man,
Speaker 1: which is that Governor Pringles? Governor Pringles, yes, Senator Pringles, Yes,
Speaker 1: we have Walter K. Pringles. He has a mustache and
Speaker 1: um under under certain light conditions, the cuttlefish eye looks
Speaker 1: like that mustache in my opinion. But the interesting thing
Speaker 1: is that, yes it has the cuttlefish ye has this
Speaker 1: signature W shape in bright light, but it's actually circular
Speaker 1: in low light. According to the W shaped pupil in
Speaker 1: cuttlefish by a math ger at All, published in Vision
Speaker 1: Research in twenty thirteen. The two main theories um were
Speaker 1: that the shape is either for camouflage, so it's just
Speaker 1: it has a weird pupil because it's doing all sorts
Speaker 1: of strange things with its chromatic force to you know,
Speaker 1: to change its its appearance and therefore it has you know,
Speaker 1: strange things going on as high as well, or that
Speaker 1: it has to do with distance calculations. It's coming down
Speaker 1: to some of the same factors that we just discussed
Speaker 1: in terms of vertical and horizontal pupils. But in this case,
Speaker 1: the researchers proposed that the w shaped pupil might aid
Speaker 1: in balancing out the vertically uneven light field of its
Speaker 1: natural habitat m Okay, So here's a quote from from
Speaker 1: that paper. Quote. While an animal's retina can deal with
Speaker 1: a wide range of light intensities in one scene, reducing
Speaker 1: this range would limit the need for rapid local adaptation
Speaker 1: during vertical gaze shifts. Since cuttlefish do not have an
Speaker 1: instant three sixty field of view, they must rely on
Speaker 1: gaze shifts to provide them with the complete view of
Speaker 1: the surrounding world. Okay, so they have to move their
Speaker 1: eyes to look around them, right, and you know, in
Speaker 1: this we have to think about light in the aquatic world,
Speaker 1: you know, where you know, the ever present darkness of
Speaker 1: the depths and then the periodic light field a realm
Speaker 1: of the upper depth. And if you're something like cuttlefish,
Speaker 1: you're having to navigate both. And it kind of comes
Speaker 1: down to some of the ideas we're discussing with with
Speaker 1: with load of the ground predators. You know, you have
Speaker 1: to sort of be adaptable to both realms, but in
Speaker 1: this case you need to be able to to simultaneously
Speaker 1: deal with the light in the darkness. By the way,
Speaker 1: coming out of the water for a second, the gecko
Speaker 1: pupil I was reading about essentially as a vertical pupil
Speaker 1: aiding in a nocturnal ambush predator's lifestyle. But it does
Speaker 1: look really cool and they are apparently really incredible hunting
Speaker 1: eyes according to some of the articles that I looked at.
Speaker 1: But then, oh, another aquatic eye of note is the
Speaker 1: dolphin pupil, and it's it's interesting that while it resembles
Speaker 1: a horseshoe or crescent, when it's fully dilated, it constricts
Speaker 1: down to two tiny openings that are sometimes referred to
Speaker 1: as a double bowl. Pupil um, and this apparently comes
Speaker 1: down to the fact that the eye the pupil shape
Speaker 1: who with dolphins has to do with dolphins or noted
Speaker 1: for having exceptional vision both in and out of the water.
Speaker 1: They know, they're they're they're they're able to to position
Speaker 1: their bodies so that they're gazing out of the water,
Speaker 1: and they have great vision in that circumstance as well.
Speaker 1: But I included a photograph here for you, Joe, and
Speaker 1: I encourage listeners to look this up as well. Um.
Speaker 1: The first picture shows the horseshoe pupil, and then the
Speaker 1: second picture shows the double pupil when everything's fully constricted. Yeah,
Speaker 1: it does look amazing though, if you do look up
Speaker 1: scientific diagrams of the eye. I think what these are
Speaker 1: explaining that's normally happening is like that the the sort
Speaker 1: of horseshoe or or U shaped pupil when it constricts,
Speaker 1: what it actually constricts down to is something that looks
Speaker 1: kind of like two earbuds connected by a wire, and
Speaker 1: the wire is just very narrow. Yes. Yes, now some
Speaker 1: of you might be wondering, Okay, you're talking about mythic
Speaker 1: figures with strange eyes, and now we've we've talked about
Speaker 1: a number of different real life organisms that have some
Speaker 1: sort of interesting eyes going on. Is it possible that
Speaker 1: that that the myth makers and the storytellers of old
Speaker 1: were inspired by eyes they saw in nature. And I
Speaker 1: didn't really find anybody talking about this, I mean outside
Speaker 1: of Yes, if you're watching some sort of modern show
Speaker 1: and reptile people show up and they have vertical slits
Speaker 1: and their eyeballs, yes, obviously somebody decided let's give them
Speaker 1: reptile eyes. Um. Though again, if they're reptile people, I mean,
Speaker 1: if they're like, I don't know, five six feet tall
Speaker 1: or something, they should probably have round eyes. What if
Speaker 1: they crawl around on their bellies all the time that's
Speaker 1: how they hunt. Oh oh, okay, then yeah, vertical slits,
Speaker 1: go for it. But I was thinking, Okay, the cuttlefish
Speaker 1: has this amazing looking eye. Any possibility there, well, I mean,
Speaker 1: the common or European cuttlefish can be found in Irish waters,
Speaker 1: and cuttlefish shells or cuttlefish bones were used as ornaments
Speaker 1: by the Celts, according to DJ Conway in the book
Speaker 1: Celtic Magic Ireland. However, it's famously light on reptile species,
Speaker 1: So I don't think geckos would have had an impact
Speaker 1: on any literary motifs. And and ultimately, I don't think
Speaker 1: anybody was pulling up any cuttlefish and checking out their
Speaker 1: their eyeballs either or you know, I've I found nothing
Speaker 1: to suggest that, but my mind went there, so I
Speaker 1: thought i'd mentioned it to everybody. You know, I think
Speaker 1: this show is a safe place to admit research dead ends.
Speaker 1: Sometimes we just got to do that. Yeah, unless there's
Speaker 1: a paper out there I'm missing, And if so, as always,
Speaker 1: if there's something we've missed, right in and let us know,
Speaker 1: we would love to be corrected. Well, should we tighten
Speaker 1: the sphincter, constrict the pupil on this one, that's right, book,
Speaker 1: what's what we should do. We should limit the light
Speaker 1: coming in at this point. But we'd love to hear
Speaker 1: from everyone out there. If there are particular mythic figures,
Speaker 1: literary figures, pop culture examples of of multi pupil, multi irist,
Speaker 1: multi lobed eyes, right in and let us know about them,
Speaker 1: Send some pictures if they exist. We would love to
Speaker 1: hear from you. Likewise, if there are other you know,
Speaker 1: we really only spend a little bit of time here
Speaker 1: with the animal world. There's so many fascinating animal eyes
Speaker 1: out there, so if there are examples that you're particularly
Speaker 1: fond of right in, let us know. And then, of
Speaker 1: course there are other areas of this that we've just
Speaker 1: touched on in these two episodes that we could easily
Speaker 1: come back and discuss more about, like oh, the evil
Speaker 1: Eye as we were discussing like that could be its
Speaker 1: own deep dive on the show, no doubt, all right.
Speaker 1: In the meantime, if you would like to check out
Speaker 1: other episodes of Stuff to Blow Your Mind, it publishes
Speaker 1: every Tuesday and Thursday, core episodes. In the Stuff to
Speaker 1: Blow Your Mind podcast feed, we have listener mail episodes
Speaker 1: on Monday, short form Artifact or Monster Fact episodes on Wednesday,
Speaker 1: and on Friday we do Weird House Cinema. That's our
Speaker 1: time to set aside most serious concerns and just talk
Speaker 1: about a strange motion picture. Huge thanks as always to
Speaker 1: our excellent audio producer Seth Nicholas Johnson. If you would
Speaker 1: like to get in touch with us with feedback on
Speaker 1: this episode or any other, to suggest a topic for
Speaker 1: the future, or just to say hello, you can email
Speaker 1: us at contact at Stuff to Blow Your Mind dot com.
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