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Children of a Thailand tribe who see with clarity beneath the waves (2016)
- deleted 7y ago[deleted]
- rblatz 7y agoI didn't realize that this was a special skill. I've always been able to see underwater, as long as the water is fairly clear. Depending on the pool I sometimes got irritated eyes, but it never really bothered me to have water in my eyes. Maybe that's why I never really had issues with my contacts either?
- WalterGR 7y agoThis subject has zero to do with eye irritation. The kids had to dive underwater and place their heads onto a panel. From there they could see a card displaying either vertical or horizontal lines. Once they had stared at the card, they came back to the surface to report which direction the lines travelled. Each time they dived down, the lines would get thinner, making the task harder. It turned out that the Moken children were able to see twice as well as European children who performed the same experiment at a later date. With the exception, I suppose, that with eye irritation it would be more difficult to complete the tests in the first place.
- tim333 7y agoThey do mention irritation: >She did notice, however, that the European kids would experience red eyes, irritated by the salt in the water, whereas the Moken children appeared to have no such problem. “So perhaps there is some adaptation there that allows them to dive down 30 times without any irritation,” she says.
- pg_is_a_butt 7y agoShould start with the thinnest lines and work backwards.
- hnick 7y agoI'm not sure it needs to be an adaptation (in a genetic sense), I think like most things our bodies just get used to it. I used to open my eyes underwater when swimming at the beach as a child on holidays, but not an adult. Having a salt water pool at home probably helped, but now that I rarely go to the beach it stings.
- deleted 7y ago[deleted]
- rblatz 7y agoRight, I just mentioned that sometimes I got irritated eyes specifically in overly chlorinated public pools or swimming in indoor pools. Since I know that is a common complaint.
- soperj 7y agoHow did they measure the clairity of the water to make sure they were the same?
- Jackim 7y agoA Secchi disk is a pretty reliable way to measure water clarity.
- jolmg 7y agoWe can all see underwater. The story is about how these children can see far clearer underwater than other people. Do you mean that you can see with total clarity? From back when I had good eyesight, I remember seeing blurry when opening my eyes underwater.
- Retric 7y agoNot the op, but I could read my wrist watch underwater. Things get fuzzy at long range, but not out of focus. More like looking through a light fog.
- mkl 7y agoNot OP. When I was a kid I could only see blurry shapes underwater, until one day it was like something clicked and suddenly I could see as clearly as in air. I have no explanation, just an anecdote, and my vision is now poor everywhere.
- fallingfrog 7y agoI have always swam underwater with my eyes open (in lakes, never tried it in seawater) but I cannot bring things into focus. I see blurry shapes that tell me where the rocks are, that’s all. You can bring things into focus like in the air? Do you have perfect vision in the air, or nearsighted, or farsighted?
- rblatz 7y agoYeah I can bring things into focus. I’ll have to jump into the pool this weekend and test it out a bit more. Also I’m very nearsighted. Without contacts in I probably see like the average person does in water.
- starpilot 7y agoPreviously: https://news.ycombinator.com/item?id=11233769 https://news.ycombinator.com/item?id=11233769
- tempsy 7y agoProbably learned like you can learn to wear contact lenses.
- rescue_dont_buy 7y agoVery interesting. Anyone else have examples, cases, etc. of this sort of thing occurring?
- scottlocklin 7y agoTHere's a great series of books by the late William Corliss documenting anomalies (across all of the sciences) containing stuff like this. https://www.science-frontiers.com/sourcebk.htm#Biology https://www.science-frontiers.com/sourcebk.htm#Biology
- itsOnMe 7y agoThese seem awesome, quite the number of anomalies he addresses.
- Hitton 7y agoNot sure what you consider it "this sort of thing", but native speakers of Australian aboriginal language Guugu Yimithirr have nearly superhuman sense of direction. They can automatically tell where is north, south, east, and west. http://pages.ucsd.edu/~jhaviland/Publications/ETHOSw.Diags.pdf http://pages.ucsd.edu/~jhaviland/Publications/ETHOSw.Diags.p...
- BurningFrog 7y agoSounds like something that might have had survival value during 50.000 years in a big nondescript landscape. Yes, I'm making an evolutionary guess.
- soperj 7y agoI believe they don't actually use left and right, but use the cardinal direction instead. So it's something they need to be constantly aware of. Ie: their kids song would go "Put your south hand in, put your south hand out.."
- clouddrover 7y ago
- Ididntdothis 7y agoAs far as I know the eyes don’t deliver perfect imagery but the brain does a lot of image processing to make the image usable (similar to a camera where what the sensor sees is pretty distorted and is corrected with software). So I would think you can train your brain to process what you see underwater clearer with a lot of practice. Just my amateur thoughts ....
- Robotbeat 7y agoWith blurry data, there's not much you can do. The adaption is about to change both the pupil's size (constricting it, like in a pinhole camera) and the lens' shape. I've tried to learn how to do this myself with very limited success. If I try to force my eyes to become blurry and then unblurry, I can notice some improvement in my ability to resolve images underwater. But this probably takes a lot of practice, and my lens is already starting to harden with age.
- Ididntdothis 7y agoThe question is whether your input is really blurry or the brain just doesn’t decode it right. A few months ago I remember reading about a method to improve eyesight by looking at things and retraining the brain. I don’t remember the details but it really worked for the author. The only problem was it was extremely boring, tedious and consumed several hours a day. But it worked. Wish I could find that article again.
- Fr0styMatt88 7y agoThere’s some really interesting stuff around this, once you start digging. I’m aphakic in both eyes (no lenses; they were removed as cataracts when I was a kid) and was blind as a child through some of the critical period of vision development. That left me having what I think can be described as bilateral amblyopia - essentially two ‘lazy eyes’, though that’s not really a good description in the sense that ‘lazy eye’ seems to be commonly misunderstood. So the weird thing is that both my eyes have a visual acuity around 20/120 or worse; that’s with correction (glasses) and it depends on the day (tiredness/dryness/etc) — but having lived this way my entire life essentially, I find it REALLY difficult to describe what it’s like to people. People think things off in the distance must be ‘blurry’, but that’s not the case at all. It’s more like ‘less detailed’, like if you turn the resolution and texture detail down. It’s not like an unfocused lens at all. There are studies I’ve found that seem to back this up. Another problem I have that’s related is a nystagmus - both my eyes oscillate involuntarily from side-to-side, separate from the normal saccades (rapid eye movements) that everyone has. You’d think I’d see the whole world oscillating from side to side - but I don’t at all. I don’t usually even notice these movements when I look in the mirror, though I can see them if I’m looking at a video of my own face. That is, most of the time. There’s one really strange failure mode I’ve observed - PWM-controlled small LED lights or segment displays like on a digital clock, particularly if they’re red but green as well, in a dark room. If it’s dim enough that I can still dimly see what surrounds the display, I can sometimes notice the LED oscillating left and right, WHILE THE STUFF SURROUNDING IT STAYS STILL. It’s really freaking weird! in short: the eye and brain are complicated!
- bryanrasmussen 7y agoSo, it seems given the last paragraphs of the article that the study cannot really be replicated. Or it would at least be very difficult to replicate.
- lph 7y agoPart of the study claimed that in a month of diving exercises you can replicate this clarity of vision underwater in European (and presumably any) children. That should be easy to reproduce. The part about a speculated adaptation to better tolerate salt water in the eyes, less so.
- Rapzid 7y agoTLDR; Children's visual acuity underwater increases with practice. There appears to be nothing special about the Moken children other than their time spent underwater using their eyes.
- metaphor 7y ago> She did notice, however, that the European kids would experience red eyes, irritated by the salt in the water, whereas the Moken children appeared to have no such problem.
- Rapzid 7y agoThat's just an observation and is there is nothing in the article to indicate it's not covered under "other than their time spent underwater using their eyes" is there? The title of the research paper is "Visual training improves underwater vision in children".
- SECProto 7y agoThat's a pretty bizarre basis for differentiation - I grew up swimming in the ocean, eyes wide open. never once did I get red eyes. Chlorine in pools is a different story.
- mschuster91 7y agoIt's not just salt, it's other pollutants. The difference between swimming in clear Croatian beaches and the average German (or Italian) waterbody is noticeable.
- 7952 7y agoI learned to swim without goggles and could see under water. It went away when I started wearing goggles. I can remember trying to go without and was shocked by how blurry the water had become.
- telesilla 7y agoYes, reading this article I also remembered having no problem as a kid who grew up next to the beach. As an adult many times removed from that life, I now need goggles when I go swimming. It's a shame the body loses that adaption so easily.
- steve_adams_86 7y agoI thought my memories of seeing in the water were false. I used to swim in deep crevasses in the river by my home and look for glimpses of trout and steelhead. I could dive down and get crayfish after spotting them from fairly high up. I remember needing to equalize many times and my body would lose buoyancy. Sometimes I'd lay on the sand or rocks and those are my most vivid memories of seeing under water. The algae on the rocks would be swaying, sunlight refracting all over, and the sound was nothing but a gentle, deep, soothing vibration of the water tumbling over stones. I recall my vision being far from perfect past 6 or 7 feet, but still pretty usable. These days I need a low volume mask and contacts if I want to see anything in the water.
- jotm 7y agoIt's an adaptation? Huh, never thought about it. I would go swimming in the sea when I was a kid without goggles, could see everything clearly. Nowadays it hurts opening my eyes underwater, I assumed it was just polluted as hell (by all reports it is)...
- amelius 7y agoAny idea what the mechanism is behind that change?
- mads 7y agoI remember being able to see clearly under water, when I was a kid. I was however sure this was not a correct memory, but maybe it was anyway. Grew up near the ocean and swam almost every day.
- GarrisonPrime 7y agoI grew up in the mountains, and only went swimming a couple of times per year at the ymca. I also recall having very clear vision underwater, and being confused as to why the adults weren’t doing such an enjoyable thing.
- cromulent 7y agoPrevious discussion: https://news.ycombinator.com/item?id=11233769 https://news.ycombinator.com/item?id=11233769
- GistNoesis 7y ago>She did notice, however, that the European kids would experience red eyes, irritated by the salt in the water, whereas the Moken children appeared to have no such problem. There is a trick that can help reduce eye irritation by salt, which may explain this : Eyes must be closed when crossing the interface between air and sea (that's usually instinctive) and also closed when crossing from sea to air (usually counter intuitive). The reason is the protective tear film get broken upon crossing when eye is open.
- EForEndeavour 7y agoI hope I remember your HN comment next time I get to swim in an ocean. Until then, could any other ocean-swimmers confirm this trick?
- GistNoesis 7y agoRemembering the trick before the salt get in the eye is also a trick to remember. Because once film is broken it needs either time to regenerate or rinsing with non salty water to regenerate. You also need to avoid touching the corner of the eyes when your hands are covered of sea water. That usually the first reflex once the eyes are irritated, (if you must touch the corner of your eyes do so with your eyes closed). This trick is easier to learn, because when your eyes are not irritated and you touch the corner of your eyes with salty hands the irritation is instantaneous.