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Children who see clearly underwater
- Grazester 11y agoThis is interesting. I am from the Caribbean and my parents a small rock(basically) off the coast of the mainland where your lively hood depended on the sea in one way or the other(fishing, diving, boat building). As a kid I would spend a lot of time in the water there swimming and diving. I felt like my underwater vision was so much better. This might not have been just a feeling then.
- YeGoblynQueenne 11y agoI've spent a lot of time in the see also but I always had blurry vision underwater. I've always preferred to use a mask when I could. Maybe it's just something you need to be aware of culturally, to even attempt it?
- speeder 11y agoI am a urban person that could see underwater, and until now I wasn't aware that it was something that could be learned, I just love diving in pools, and could not afford any equipment, so I got used to diving with eyes open, even in stupid high chlorine pools, and I don't need to mechanically close my nostrils either.
- Coding_Cat 11y agoHuh, I didn't know this was something special. I used to swim underwater with my eyes open all the time when I was little and I could see underwater just fine like the article describes. I just assumed everyone could :). Although I couldn't do it in salt water, it stung my eyes too much but that might also be due to me learning to swim in pools instead of the sea.
- awqrre 11y agoThey are talking about sea water...
- Coding_Cat 11y agoI know, but the crux of the article seems to be that you shouldn't be able to see underwater even if you can keep your eyes open. I could/can see underwater just fine but only if I can keep my eyes open of course. I cannot keep my eyes open in salt water, but that might be a lack of acclimatization is what I'm saying.
- mattdeboard 11y agoHm. Salt water is (according to my google-fu) denser than fresh water. The article says, "When the eye is immersed in water, which has about the same density as the cornea, we lose the refractive power of the cornea..." I wonder if this refers to salt or fresh water. Maybe both, if the density delta between the two is trivial.
- mtmail 11y agoThe article is about keeping that clear view until adult life.
- Coding_Cat 11y agoNo, it isn't: Gislen was able to test a few Moken adults in the same way. They showed no unusual underwater vision or accommodation – perhaps explaining why the adults in the tribe caught most of their food by spear fishing above the surface. “When we age, our lenses become less flexible, so it makes sense that the adults lose the ability to accommodate underwater,” says Gislen.
- cfcef 11y agoYou can see underwater, but you don't see as well as they do: > 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.
- Retric 11y agoI suspect this is mostly just a question of how much time people spend under water. When I used to swim a lot I did not notice my vision being worse underwater. I could easily read an underwater wrist watch for example. PS: I still have better than 20/20 vision. But, I think your eyes age faster than most people suggest as I can't see as well even at just 35 vs 15.
- alxndr 11y agoI'm 31 and can also see pretty clearly in freshwater; don't recall trying to see in sea water though.
- chrisb 11y agoThis links to something that's occasionally interested me. Are you able to consciously refocus your eye? By this I mean stare at an object (with one eye), and consciously make it go in and out of focus, whilst always staring straight at it. I find that I can do this to a certain extent - is this something that most people can do?
- Coding_Cat 11y agoThere are hidden picture books which look like random noise until you manage to focus your eyes 'behind' the book. I could never do that but others could. So I would say yes, you can with some effort.
- chrisb 11y agoAre you talking about "Magic Eye" pictures like this: http://mentalfloss.com/article/29771/why-cant-some-people-see-magic-eye-pictures http://mentalfloss.com/article/29771/why-cant-some-people-se... ? If so, this isn't really what I mean. I mean with just one eye, being able to consciously refocus that eye. For example, looking at this writing on your screen able to make that go in and out of focus.
- Coding_Cat 11y agoI can do that, focusing outward is easier than inward though. Unless I hold a finger in between the screen and my eye, then it's the opposite.
- chenglou 11y agoCan you elaborate on the finger trick? I can still only focus outward (aka blurring, if that's what you mean)
- Coding_Cat 11y agoI can bring my finger into focus, drawing my focal point in front of the screen, and if then remove my finger I can hold that focus (with about a 50% success rate). Perhaps that is cheating a little ;).
- eugenekolo2 11y agoIs their vision better than using goggles?
- deleted 11y ago[deleted]
- mirimir 11y agoWhen I was young, as I recall, I could see better underwater than normally. I'm very nearsighted.
- mikekchar 11y agoI had the same experience. It's strange. I always thought that was normal (that you could see better underwater than above water). I don't really like swimming, so I haven't done it more than once or twice as an adult. Now I'm curious if I would have the same experience.
- mirimir 11y agoMaybe swimming a lot underwater causes nearsightedness. But then, in the article, I see: > She thought the first theory was unlikely, because a fundamental change to the eye would probably mean the kids wouldn’t be able to see well above water. A simple eye test proved this to be true – the Moken children could see just as well above water as European children of a similar age.
- Pyxl101 11y agoDid you know that your eyes can adapt to being open in sea water? When you first open them underwater in the sea, they'll sting like crazy. If you persist - or at least this was the case for me, that effect will go away, and you can open them underwater without pain. They will still be unfocused, though, of course. From the article, it sounds like you need to practice for a while before the eye learns how to focus underwater: > Gislen wondered whether the Moken children had a genetic anomaly to thank for their ability to see underwater or whether it was just down to practice. To find out, she asked a group of European children on holiday in Thailand, and a group of children in Sweden to take part in training sessions, in which they dived underwater and tried to work out the direction of lines on a card. After 11 sessions across one month, both groups had attained the same underwater acuity as the Moken children. Perhaps this only works for children, who seem somehow more biologically adaptable? The body is quite adaptable in general so I would believe it that people who swim regularly could see better underwater. I'm glad to have the science though to study the effect more rigorously.
- pcl 11y agoDid you know that your eyes can adapt to being open in sea water? Wow... I didn't know that. Losing my mask and panicking while diving has always been a concern of mine. I'll have to try this out. Regardless of being able to see clearly, it'd be great to just not be bothered by an onslaught of seawater.
- iamphilrae 11y agoYour tears are very salty so seawater actually isnt that different from the water that's already in your eyes. A lot of panic people have in opening their eyes in seawater stems from their experience of chlorinated swimming pools - which absolutely stings like hell!
- narag 11y agoI don't know why, but seawater in my eyes absolutely causes me pain, not panic.
- PhantomGremlin 11y agoMaybe I'm just a wuss, but the only thing I could think of is why would someone want to open their eyes underwater? E.g. a quick google turned up: a liter of seawater collected in marine surface waters typically contains at least 10 billion microbes and 100 billion viruses[1] No, thank you. [1] http://www.the-scientist.com/?articles.view/articleNo/36120/title/An-Ocean-of-Viruses/ http://www.the-scientist.com/?articles.view/articleNo/36120/...
- eru 11y agoJust compare how many microbes and viruses are already living on a square-centimetre of your skin.
- mattdeboard 11y agoFishing, i.e. food & money.
- PhantomGremlin 11y agoYes, of course, the people in Thailand do it to survive. I was thinking more along the lines of first-world people, especially children. E.g. exposing "European children on holiday in Thailand" to what I stereotype as the fetid waters off the coast of third world countries. It may be a stereotype, but that doesn't mean it's not true. I'd venture that the phrase "sewage treatment plant" is not part of the vernacular there.
- eru 11y ago> E.g. exposing "European children on holiday in Thailand" to what I stereotype as the fetid waters off the coast of third world countries. Thailand ain't exactly third world. (The waters can be dirty, though.)
- dredmorbius 11y agoRandall Munroe in an xkcd What If cited a statistic that still astounds me: the mortality of any given living cell in the ocean is 20%. Per day. I'll dig up the ref on request, but that's just ... staggering. https://www.reddit.com/r/dredmorbius/comments/1vyanj/viral_soup_and_the_red_queens_race/ https://www.reddit.com/r/dredmorbius/comments/1vyanj/viral_s...
- blubb-fish 11y agoCould the BBC please stop promoting their stuff here? Thanks!
- DanBC 11y agoThe submitter has posted 2 links to the BBC in their last 30 submissions. The last 30 submissions of bbc.com were submitted by about 25 different accounts. Why do you think this article doesn't belong here?
- eggy 11y agoMy last job for 6 years was fixing hydraulics and electrical systems under water, among other things. I am now 51, and at that time, my presbyopia, or farsightedness increased. I wear +1.50 reading glasses topside. Just old age, and the len's inability to accommodate as much as when you are younger. I could open my eyes, maskless in fresh or salt water. And it is not chlorine that burns your eyes in most cases. If you think you smell chlorine, you're mistaken; chlorine is odorless. It is the byproducts of free chlorine that eat abundant organic matter that creates chloramines that you are smelling. A sure indicator they did not maintain a minimum level of free chlorine to begin with. In any case, I was able to improve my work underwater over those six years. If you discount feeling with my hands, what augmented my ability was not pupil dilation or lens accommodation, but the brain's processing. It has been proven if you concentrate while reading without your reading glasses, you can train your years of reading to recognize the letter shapes in their new blurry appearance. Not magic here, hard work. What I would be interested in is did she change it from merely horizontal and vertical lines? I can easily see the brain also augmenting their ability to accommodate their lens and pupil dilation to make their ability even more impressive. This would explain how the European children may have 'thought' they saw clearer, but it was the brain clarifying their perception and not any lens or pupil dilation in their short study.
- david-given 11y agoI remember hearing from someone who was on a long cruise trip, and on their first day, lost their glasses without hope for replacement. So they just had to cope with the rest of the trip without. They said that it took a while to learn to cope, but once they did their short-sightedness didn't affect everyday life at all, apart from not being able to read. This included things like playing tennis. I'm -4.5 in both eyes, and, interestingly, if I take my glasses off I can just about make out the words I'm typing here without adjusting the zoom level; mostly from shape. Zooming in a couple of notches makes the letters appear. Blurry and distorted, but legible (just). I can totally believe that practice would make me reasonably functional.