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Captain Kidd
2005-Aug-01, 02:19 PM
We went to the Lost Sea (http://www.thelostsea.com/home.htm) this past weekend. It was rather neat taking a boat ride on an underground lake. Some big fish down there too. (Imported trout, originally intended to be used to find the outlet, by tagging I'm assuming. But the fish decided the lack of fishermen was a bonus and never left. That or the outlet is too small to let a fish swim through.)

However, one thing the guide said bugged me a little. They did the standard turn the lights out to experience total darkness. While off, the guide said something that I hadnít heard before.

After three weeks of total darkness your eyes burn out due to the strain of attempting to see.

Iíve never heard that before. My wife has an uncle who did get lost in a cave for 8+ hours and when they rescued him, it was night and the moonlight was enough to make him have to cover his eyes. But thatíd be due to how dilated his eyes had become I've assumed.

Can anybody, err, shed some light on this? Googling has returned some studies on light depravation on young monkeys and cats while developing, but I didnít find anything on adults going blind due to loss of light.

Taks
2005-Aug-01, 02:30 PM
my guess is that is nonsense. the reaction to bright lights after being in the dark is due to dilation of the pupils, a muscle reaction. they can only get so wide and they get there pretty quickly. i can't think of any other "strain" this guy may be referring to...

i've been in some caves (lead mines, actually) in my home state (MO) and they do the same thing. bring everyone down deep and turn out the lights (after making sure we're sitting). it is dark, and quite eery, but once my eyes got used to the fact there was no light, all was well (about 5 minutes). they have a protocol if the lights fail. sit still, you'll be found! i suppose it wouldn't do you much good to crawl around and drop off into the depths...

taks

Stardate
2005-Aug-01, 02:32 PM
Off or on topic: I just watched on MSNBC about Poland during WWII. They were walking through the sewage tunnels for 20 hours in total darkness, and after exiting, some were blind for up to three days. The program said the blindness was due to the waste fumes. Others died or went mad during the trek to safety (only later to be captured).

Taks
2005-Aug-01, 02:39 PM
i'd say the waste fumes contributed to the madness, too. of course, i wonder what trolling around in an abandoned lead mine did for me? :)

taks

Eoanthropus Dawsoni
2005-Aug-01, 02:43 PM
However, one thing the guide said bugged me a little. They did the standard turn the lights out to experience total darkness. While off, the guide said something that I hadnít heard before.

After three weeks of total darkness your eyes burn out due to the strain of attempting to see.



Total nonsense. But commercial cave tours are known for that sort of whacky **.

Stardate
2005-Aug-01, 02:47 PM
i'd say the waste fumes contributed to the madness, too. of course, i wonder what trolling around in an abandoned lead mine did for me? :)

taks
How many fingers am I holding up right now? :)

Donnie B.
2005-Aug-01, 02:51 PM
How many fingers am I holding up right now? :)
You're both holding up three. 8)

Stardate
2005-Aug-01, 03:11 PM
How many fingers am I holding up right now? :)
You're both holding up three. 8)
:-#

What are the studies on POW's kept in total dark isolation? Does anyone know? I bet there is some correlation to temporary blindness after their release.

Captain Kidd
2005-Aug-01, 03:20 PM
Total nonsense. But commercial cave tours are known for that sort of whacky **.
As is what I thought too.

The rods and cones would regernate completely and your irises would dilate to full open. So that's a nasty 1-2 punch if you're then pegged in the face by a searcher's flashlight or don't take precautions upon exiting the cave. But to "burn out" seemed to be reaching a bit.

That uncle I mentioned earlier started hallucinating that he saw monsters/demons coming for him and actually tried to attack the rescuers at first. But then he's always been a bit of a nut.

They also claimed that the former "Cavern Tavern", which was located at the bottom of 132 steps, had enough of an air pressure increase that the effects of alcohol were extremely reduced (actually he said the patrons didn't get drunk at all). Then upon reaching the top of the steps, the lower air pressure would cause them to experience the alcohol fully and fall down the steps. Many were seriously injured or killed and it forced the business to close.

I think the effort of climbing 132 steps extremely drunk caused them to pass out and then fall is more like it. The standard riser today is 5-7 inches. Now I doubt these farmers built the CT to codes, if there even was stair riser codes in the 40's. But assuming 7 inches per step, that's approximately 80 feet.

They'd have to climb more than that just to reach the cave enterance. So any pressure gained in going down into the cave would still be less than the valley in which they lived. And since you can get drunk at sea level... Again my **-o-meter was pegging out.

Stardate
2005-Aug-01, 03:29 PM
After three weeks of total darkness your eyes burn out due to the strain of attempting to see.
So we're talking about apples and oranges? Who'd be in a cave for three weeks in total darkness? Big difference from a few minutes!

Eoanthropus Dawsoni
2005-Aug-01, 03:52 PM
That uncle I mentioned earlier started hallucinating that he saw monsters/demons coming for him and actually tried to attack the rescuers at first. But then he's always been a bit of a nut.



The hallucinations don't surprise me. When the brain is denied sensory input it tends to make up it's own. Add to that the emotional stress of being lost in total darkness and even a normal person might be acting a bit nutty.

Donnie B.
2005-Aug-01, 06:37 PM
There are multiple mechanisms for accomodation to light levels. In addition to the relatively rapid pupil dilation, there are slower chemical changes that affect the retina's response to light. I don't know many details, unfortunately, but it's moot anyway -- there's no way that these could lead to permanent blindness. And you can't will yourself to blindness by straining.

I wonder if the guide at the caverns might have been confused with the evolutionary changes that lead to eyeless fish and the like? Of course, those changes occur over many generations, not in a single individual. But Lysenkoism dies hard.

Stardate
2005-Aug-01, 06:41 PM
There are multiple mechanisms for accomodation to light levels. In addition to the relatively rapid pupil dilation, there are slower chemical changes that affect the retina's response to light. I don't know many details, unfortunately, but it's moot anyway -- there's no way that these could lead to permanent blindness. And you can't will yourself to blindness by straining.

I wonder if the guide at the caverns might have been confused with the evolutionary changes that lead to eyeless fish and the like? Of course, those changes occur over many generations, not in a single individual. But Lysenkoism dies hard.
I don't think the guide was talking about total blindness, but temporary blindness. I do think this is possible.

Donnie B.
2005-Aug-01, 07:01 PM
This reminds me of the story of the blind man whose sight was suddenly restored -- in the middle of a pitch-black night (or maybe it was in the bowels of an unlit cavern!) He yelled and danced around, saying "I can see! I can see!"

His companion, confused, asked him how he could tell. He answered, "I see blackness!"

-- which is about as plausible as the guide's remarks, IMHO.

Taks
2005-Aug-01, 07:08 PM
13 fingers, btw... all thumbs, actually.

i would think sensory deprivation wouldn't be an issue unless ALL the senses were deprived. there are plenty of cases of people losing their sight after years with it, a suitable analogy maybe, and they aren't running around stark raving mad from hallucinations. of course, anecdotal conjecture at best, but i'd think we'd have at least heard of it! :)

i agree, btw, that weeks vs. minutes is different in terms of long-term physiology. however, i was mostly noting that within a few minutes your eyes completely stop "straining" to see. IMO, it's actually rather comforting once they "relax". much easier to focus on hearing, too.

taks

Stardate
2005-Aug-01, 07:22 PM
Being the dork I am, sunlight hurts my eyes.

I work a midnight shift, and the building shuts the lights off (where I walk for safety) after dusk. I shut the lights off where I work, except for the glare of the computers. I monitor hundreds of people worldwide conveniently located on computer screens.

I wear sunglasses when I go out in daylight, even if its not sunny. I have over a 100 pairs. My eyes have become so conditioned to darkness, that daylight just kills me. No, I'm not a vampire.

My home is darkended by blackness. My pupils dialate to total black when seen by others.

I'm only bringing this up because I believe there is a correlation with being blind and darkness.

[edit - you know what I mean, don't you?]

Captain Kidd
2005-Aug-01, 07:28 PM
I don't think the guide was talking about total blindness, but temporary blindness. I do think this is possible.
No, he meant permanent blindness; as in buy a cane and start looking for a helper dog Ďcause it ainít coming back.

Going for the shock factor basically.

Stardate
2005-Aug-01, 07:31 PM
I don't think the guide was talking about total blindness, but temporary blindness. I do think this is possible.
No, he meant permanent blindness; as in buy a cane and start looking for a helper dog Ďcause it ainít coming back.

Going for the shock factor basically.
Well, then you're doomed. How many fingers am I holding up? :lol:

Eoanthropus Dawsoni
2005-Aug-01, 07:50 PM
i would think sensory deprivation wouldn't be an issue unless ALL the senses were deprived. there are plenty of cases of people losing their sight after years with it, a suitable analogy maybe, and they aren't running around stark raving mad from hallucinations. of course, anecdotal conjecture at best, but i'd think we'd have at least heard of it! :)





Removing all stimuli will certainly do it, but even if one of the senses is taken away the brain will often make up for it by providing substitutes.

In a sound proof room people will hear things, in total darkness people will see things.

farmerjumperdon
2005-Aug-01, 08:23 PM
Being the dork I am, sunlight hurts my eyes.

I work a midnight shift, and the building shuts the lights off (where I walk for safety) after dusk. I shut the lights off where I work, except for the glare of the computers. I monitor hundreds of people worldwide conveniently located on computer screens.

I wear sunglasses when I go out in daylight, even if its not sunny. I have over a 100 pairs. My eyes have become so conditioned to darkness, that daylight just kills me. No, I'm not a vampire.

My home is darkended by blackness. My pupils dialate to total black when seen by others.

I'm only bringing this up because I believe there is a correlation with being blind and darkness.

[edit - you know what I mean, don't you?]

I read the "No, I am not a vampire" line the way Arnold said "It's not a tumor."

But out of curiosity, ever hear a song titled "How Come I Can't See You In My Mirror" by a gentleman named Tonio K? I gotta do a search for the lyrics.

Taks
2005-Aug-01, 10:32 PM
blue eyed folk such as myself are extremely sensitive to light as well. i have a hard time without sunglasses. of course, i have a hard time not losing my sunglasses so i spend a lot of time squinting.
taks

Apothis
2005-Aug-01, 11:31 PM
I'm blue eyed, and I have noticed that too. I often find myself squinting, and having to wear sunglasses on overcast days. 8)

Captain Kidd
2005-Aug-01, 11:39 PM
Hazel here and sunlight doesn't do me much good either. I'm starting to develop crow's feet; distinguished my wife says, old I say.

Any idea why blue-eyed people are more sensitive? Total WAG: the lighter color lets light seap through the iris?

Apothis
2005-Aug-02, 12:25 AM
I really don't know why blue eyed people are more sensitive. One would think brown or other dark colors would be more sensitive because those colors absorb more light than they reflect. Obviously this is not the case.

Captain Kidd
2005-Aug-02, 12:39 AM
Hmm found a site (http://www.ofcn.org/cyber.serv/hwp/hwc/eye/news/eye045.html) that somebody claiming to be a MD says it's due to less pigment being in the eye.

WARNING: It's also black text on a pink background that made me flinch the entire time I was trying to read it too.

Apothis
2005-Aug-02, 12:47 AM
Interesting site. It seems to make sense.

Stardate
2005-Aug-02, 02:35 AM
I read the "No, I am not a vampire" line the way Arnold said "It's not a tumor."

But out of curiosity, ever hear a song titled "How Come I Can't See You In My Mirror" by a gentleman named Tonio K? I gotta do a search for the lyrics.
No. :)

I have hazel colored eyes, too.

Taks
2005-Aug-02, 05:31 AM
i would think that having less pigment means more light reflected around in the eye itself, perhaps even between the iris and cornea? or maybe it's just that whatever causes the blue eyes also has an impact on the number of rods (or is it cones?). dunno, just guessing.

either way, i do have very sharp night vision, which would tend to agree with more light sensors. whether the cause is the same is unknown to me.

taks

Gillianren
2005-Aug-02, 07:34 PM
remember that lighter-coloured eyes (hazel as well, in fact the same colour as the Afghani woman on the National Geographic cover) were an adaptation of northern peoples, along with lighter skin pigmentation. as to why it works, well, I don't know. not my field. but you're about as likely to see a blue-eyed Bantu as you are to see a brown-eyed Swede. (okay, less likely. but which eye colour do you automatically assume either person would be more likely to have?)

Taks
2005-Aug-02, 09:20 PM
i suppose i get the olive skin from the crazy italian blood in my family (only recently discovered, crazy germans didn't want to admit it) and the blue eyes from the crazy irish blood in my family. good mix of heavy drinkers, that's for sure. i continue the family tradition, though i no longer have any idea where i should place credit for my misdeeds. :)

taks

Izunya
2005-Aug-03, 05:34 AM
i would think sensory deprivation wouldn't be an issue unless ALL the senses were deprived. there are plenty of cases of people losing their sight after years with it, a suitable analogy maybe, and they aren't running around stark raving mad from hallucinations. of course, anecdotal conjecture at best, but i'd think we'd have at least heard of it! :)

Mammoth Cave was rrreeeally quiet, to the point of spooky. Lost Sea, on the other hand--yes, I've been there--had a dripping, stalagmite-building sort of sound, at least in some bits. IIRC, at least. It's been a lot longer since I went to Lost Sea.

My point is that being lost in Mammoth Cave would effectively deprive you of all light and any sounds but your own. Now, Helen Keller wasn't insane, but she also lost her senses very young--age three, maybe?--so her brain must have still been very flexible. I think it's rather more likely for an adult, deprived of all sight and most sounds and probably panicked, to start hallucinating, or even have lasting mental problems.

Which doesn't mean it always happens. Our Mammoth Cave guide told us a story about a guy who got lost in the cave sometime back in the eighteen hundreds, and came out white-haired and half-crazed--and while this was a good tavern yarn, none of his acquaintances particularly cared, because they knew he had already been white-haired for years, and half-crazed was either a generous assessment or an improvement. Somehow these details never make it into the urban legends, do they?

Hmm . . . urban legends. Wonder if they have this one on Snopes.

Izunya

Taks
2005-Aug-03, 06:58 AM
there's a bunch of lead mines south of st. louis, near desloge in a little town called leadville (hmmm...). as kids, we used to run up the chat piles (several hundred feet high) and play. hindsight says that may explain a few of these weird biological anomalies i've been experiencing for oh, i don't know, 25 years or so? :)

anyway, we used to go in there and they'd always do the lights off trick. used to be able to dive in the natural springs (still rising, that's why the mines shut down) until some divers got freaked out and ended up ded.

taks

Eoanthropus Dawsoni
2005-Aug-03, 02:38 PM
I used to do caving when I was younger. I still love caves, but living in North Dakota means a drive of several hundred miles to any decent cave. And with so many other things to do with my time, I never seem to be able to justify a caving trip anymore. When caving I used to enjoy turning off my light and experiencing the dark silence. But I knew that I could always turn my light back on whenever I wanted, and I always carried a couple extra sources of light so that even if one died I would still have backup lighting. I can imagine that being lost underground with NO light would be very disconcerting.

When I visit show caves I am always amused by the ** being spewed by the guides. Very little of what I have heard is factual, and leaves me with the impression that show caves hire as guides the people who can't get jobs as carneys.

Stardate
2005-Aug-03, 05:03 PM
I used to do caving when I was younger. I still love caves, but living in North Dakota means a drive of several hundred miles to any decent cave. And with so many other things to do with my time, I never seem to be able to justify a caving trip anymore. When caving I used to enjoy turning off my light and experiencing the dark silence. But I knew that I could always turn my light back on whenever I wanted, and I always carried a couple extra sources of light so that even if one died I would still have backup lighting. I can imagine that being lost underground with NO light would be very disconcerting.

When I visit show caves I am always amused by the ** being spewed by the guides. Very little of what I have heard is factual, and leaves me with the impression that show caves hire as guides the people who can't get jobs as carneys.
Do you have hazel eyes like me (with a hint of blue on the outer edge)? My grandparents and dad are from North Dakota. I'm a redhead offspring with no pigmentation what-so-ever.

Eoanthropus Dawsoni
2005-Aug-03, 05:07 PM
Do you have hazel eyes like me (with a hint of blue on the outer edge)? My grandparents and dad are from North Dakota. I'm a redhead offspring with no pigmentation what-so-ever.

My eyes are blue, but my hair was red.

Stardate
2005-Aug-03, 05:17 PM
Do you have hazel eyes like me (with a hint of blue on the outer edge)? My grandparents and dad are from North Dakota. I'm a redhead offspring with no pigmentation what-so-ever.

My eyes are blue, but my hair was red.
Are you a Cartwright or a Peterson/sen? Red is not a common color!

Eoanthropus Dawsoni
2005-Aug-03, 05:21 PM
Nope.

I am 1/4 Irish. There are a lot of redheads in that part of the family.

Stardate
2005-Aug-03, 05:35 PM
Nope.

I am 1/4 Irish. There are a lot of redheads in that part of the family.
All redheads come from Ireland.

Okay, I've got only mc's to counter you besided english blood. Lay you hand, man!