The Straight Dope

Go Back   Straight Dope Message Board > Main > General Questions

Reply
 
Thread Tools Display Modes
  #1  
Old 01-12-2010, 04:29 AM
xash xash is offline
Ogministrator
Moderator
 
Join Date: Jan 2001
Location: Palo Alto, CA
Posts: 4,133
At what temperature will your eyeballs freeze?

And what keeps them from freezing before that temperature?

This post got me wondering:

Quote:
Originally Posted by MoodIndigo1 View Post
-40 without wind is great weather for a walk. At that temperature, it's usually sunny outside, great for the morale. The snow becomes sort of brittle and it makes a sort of a crystalline sound underfoot. I love it.
Assume no eye protection.

Corollary 1: Is there a temperature at which our eyeballs will freeze before we hit hypothermia?

Corollary 2: If our eyeballs froze, and we were still conscious, what would be the resultant effect on our vision?
Reply With Quote
Advertisements  
  #2  
Old 01-12-2010, 04:35 AM
The Great Philosopher The Great Philosopher is offline
Registered User
 
Join Date: Dec 2000
Surely the eyes, containing blood vessels and live tissue as they do, would be kept warm artificially by the body, in the same way the skin and the organs are? In order for your eyes to freeze your body temperature would have to fall so low that you would by definition have hypothermia. I'd hope anyway - otherwise I'll be worrying about my eyes freezing next time I go out...
Reply With Quote
  #3  
Old 01-12-2010, 05:02 AM
Rhythmdvl Rhythmdvl is offline
Charter Member
 
Join Date: Oct 1999
Location: Shakedown Street
Posts: 12,412
Quote:
Originally Posted by xash View Post
Assume no eye protection.
Do we get to carry a mirrored shield?





Don't some seabirds or the like have a specialized artery/vein arrangement in their legs to maintain body temperature? Given how effective that is, I'd say TGP's point about constant blood flow would either prevent freezing or lead to horrid complications before obtaining eyece cubes.

Can ocular experts describe how much of the eye has blood going through it compared to the overall volume of fluid? Perhaps it can freeze quick enough to block the capillaries and prevent circulation to the eye. Man that's gonna hurt.
Reply With Quote
  #4  
Old 01-12-2010, 05:10 AM
xash xash is offline
Ogministrator
Moderator
 
Join Date: Jan 2001
Location: Palo Alto, CA
Posts: 4,133
Quote:
Originally Posted by The Great Philosopher View Post
Surely the eyes, containing blood vessels and live tissue as they do, would be kept warm artificially by the body, in the same way the skin and the organs are?
Good point, but assume you weren't walking around naked. Instead you had the best protection from the weather for the rest of your body, with just your eyes exposed. To borrow a phrase, when would they become eyece cubes and iceplode?
Reply With Quote
  #5  
Old 01-12-2010, 06:00 AM
abel29a abel29a is offline
Guest
 
Join Date: Jun 2006
No factual answer, but I've been out in -45DEG Celsius weather with some wind (I'm guessing -50 -- -55 effective), and altough your eyes will often tear up and those tears will freeze quickly, as long as you clean away this from time to time - no ill effects.
Reply With Quote
  #6  
Old 01-12-2010, 06:57 AM
Machine Elf Machine Elf is offline
Guest
 
Join Date: Feb 2007
I could see problems if you had extreme cold, a major wind, and deliberately held your eyes wide open for extended periods. But I think it's natural to squint your eyes down to slits if it's very windy; your eyelashes help to occlude what littl gap remains, preserving a protected pocket of air in front of your eyeballs.

Your eyeballs are being cooled on their front surface by convection from a gas (air), and warmed from behind by convection and conduction from 98.6-degree liquid. Given the above paragraph and this one, my gut reaction is that it would have to be unnaturally cold out to risk freezing the surface of your eyeballs.
Reply With Quote
  #7  
Old 01-12-2010, 07:08 AM
tsukaesugi tsukaesugi is offline
Guest
 
Join Date: May 2003
This is fiction, and not an answer to the question, but the novel "The Terror" by Dan Simmons, has a very memorable scene where a character's eyeballs freeze.

I immediately thought of that when I saw this thread.
Reply With Quote
  #8  
Old 01-12-2010, 08:34 AM
Mangetout Mangetout is offline
Charter Member
 
Join Date: May 2001
Location: England
Posts: 51,914
Quote:
Originally Posted by Joe Frickin Friday View Post
I could see problems if you had extreme cold, a major wind, and deliberately held your eyes wide open for extended periods.
Even so, I think you'd suffer frostbitten corneas at worst - for the eyeball itself to freeze, I think the whole outer surface of the head has to be doing the same.
Reply With Quote
  #9  
Old 01-12-2010, 08:40 AM
Philster Philster is offline
Guest
 
Join Date: Aug 2000
Quote:
Originally Posted by The Great Philosopher View Post
Surely the eyes, containing blood vessels and live tissue as they do, would be kept warm artificially by the body, in the same way the skin and the organs are?....
What's 'artificial' about it?
Reply With Quote
  #10  
Old 01-12-2010, 09:24 AM
Rhythmdvl Rhythmdvl is offline
Charter Member
 
Join Date: Oct 1999
Location: Shakedown Street
Posts: 12,412
Quote:
Originally Posted by Philster View Post
What's 'artificial' about it?
What, you don't know? Oh man! Here, put on these glasses.
Reply With Quote
  #11  
Old 01-12-2010, 11:37 AM
cjepson cjepson is offline
Guest
 
Join Date: Oct 2007
I hope y'all will pardon the hijack, but this reminded me of something I read in a book on Antarctica. At some extremely low temperature (around -60 F, perhaps?), just breathing the air will cause you to eventually die of hypothermia, no matter how warmly you're dressed.
Reply With Quote
  #12  
Old 01-12-2010, 01:44 PM
Mr. Excellent Mr. Excellent is offline
Guest
 
Join Date: Feb 2003
Quote:
Originally Posted by Rhythmdvl View Post
What, you don't know? Oh man! Here, put on these glasses.
No!
Reply With Quote
  #13  
Old 01-12-2010, 02:21 PM
CookingWithGas CookingWithGas is offline
Charter Member
 
Join Date: Mar 1999
Location: Tysons Corner, VA, USA
Posts: 9,775
Although posters describe experiences in extremely cold weather, and still have their eyeballs intact, you always hear weatherpeople tell you not to go outside with exposed skin when it's, say, below zero, due to the risk of frostbite. But they never tell you to cover your eyes, and it seems that the eyes would be more prone to freezing than skin since they have a large water content (my speculation only).

So if they don't freeze, or at least get damaged, why not, if my fingers would get frostbite without gloves pretty quickly in that kind of cold?
Reply With Quote
  #14  
Old 01-12-2010, 02:36 PM
Machine Elf Machine Elf is offline
Guest
 
Join Date: Feb 2007
Quote:
Originally Posted by CookingWithGas View Post
Although posters describe experiences in extremely cold weather, and still have their eyeballs intact, you always hear weatherpeople tell you not to go outside with exposed skin when it's, say, below zero, due to the risk of frostbite. But they never tell you to cover your eyes, and it seems that the eyes would be more prone to freezing than skin since they have a large water content (my speculation only).

So if they don't freeze, or at least get damaged, why not, if my fingers would get frostbite without gloves pretty quickly in that kind of cold?
Cuz your eyeballs are pretty well protected. They are positioned in depressions in your face, and are in little pockets formed by your eyelids. Your eyelashes help keep the wind from blasting away the tiny pocket of above-freezing air immediately in front of each eyeball. You blink on a regular basis, wiping the surface of your eyes with a warm eyelid (your eyelids, when not shut, are retracted behind your eyebrows). The surface of your eye is a (approximately) flat region, not a narrow appendage like your fingers.
Reply With Quote
  #15  
Old 01-12-2010, 03:21 PM
Stealth Potato Stealth Potato is offline
Guest
 
Join Date: Nov 2004
Quote:
Originally Posted by xash View Post
To borrow a phrase, when would they become eyece cubes and iceplode?
Icy what you did there.
Reply With Quote
  #16  
Old 01-12-2010, 03:28 PM
RedSwinglineOne RedSwinglineOne is offline
Guest
 
Join Date: Jan 2007
Quote:
Originally Posted by CookingWithGas View Post

So if they don't freeze, or at least get damaged, why not, if my fingers would get frostbite without gloves pretty quickly in that kind of cold?
Because your body will limit the amount of blood sent to the extremities in an effort to keep your internal organs warm. Frostbite is better than death. Most of the stuff in your head though is pretty important so it is not subject to the restriction of blood circulation.

Last edited by RedSwinglineOne; 01-12-2010 at 03:29 PM..
Reply With Quote
  #17  
Old 01-12-2010, 04:11 PM
moldybread moldybread is offline
Guest
 
Join Date: Sep 2009
My wife gives me that icy cold stare alot. Ill ask her!
Reply With Quote
  #18  
Old 01-12-2010, 05:05 PM
xash xash is offline
Ogministrator
Moderator
 
Join Date: Jan 2001
Location: Palo Alto, CA
Posts: 4,133
Quote:
Originally Posted by cjepson View Post
I hope y'all will pardon the hijack, but this reminded me of something I read in a book on Antarctica. At some extremely low temperature (around -60 F, perhaps?), just breathing the air will cause you to eventually die of hypothermia, no matter how warmly you're dressed.
Interesting. This is relevant, because it at least puts a lower bound to the temperature at which MoodIndigo1 can go for a walk.

Can anyone find a ceyete for this? If this is true, and we hit hypothermia by just breathing the air, regardless of clothing cover, then it appears from responses in this thread that we won't make eyece cubes before we deye of eyepothermia.

And no one seems to have taken a stab at this part of the question (assume a hypothetical scenario, since it seems unlikely that we'll be conscious in such a state):

Corollary 2: If our eyeballs froze, and we were still conscious, what would be the resultant effect on our vision?
Reply With Quote
  #19  
Old 01-12-2010, 06:51 PM
Mangetout Mangetout is offline
Charter Member
 
Join Date: May 2001
Location: England
Posts: 51,914
Quote:
Originally Posted by xash View Post
Corollary 2: If our eyeballs froze, and we were still conscious, what would be the resultant effect on our vision?
Assuming they froze gradually from the front to the back...

Partial loss of vision similar to a cataract
Visual phosphene-type disturbances caused by the extra pressure on the retina as the eyece expands
Total loss of sight once the retina starts to freeze. In the absence of proper input, the brain might still register some phenomena that appear visual, but with no particular correlation to the real world.
Reply With Quote
  #20  
Old 01-12-2010, 07:04 PM
code_grey code_grey is offline
BANNED
 
Join Date: Dec 2008
Posts: 2,207
notice that you can still, sort of, see if you squint your eyes, thus reducing their exposed surface and putting the eyelashes in front of it. Presumably if you have narrow eyes like people from Mongolia (a place with windy cold winters) this gets easier to do.

That being said, temperatures above -50C were considered sufficiently warm to do serious work (not just walking around squinting) in Siberian prison labor camps under Stalin. (For free people the minimal allowed temperature was usually much higher, I think -30C or -35C).

I guess the moral of the story is, our eyes are capable of handling pretty much any temperature found in the regions where humans actually live, even without the eye shape of the northern Asian people.
Reply With Quote
  #21  
Old 01-12-2010, 07:35 PM
xash xash is offline
Ogministrator
Moderator
 
Join Date: Jan 2001
Location: Palo Alto, CA
Posts: 4,133
Quote:
Originally Posted by Mangetout View Post
Total loss of sight once the retina starts to freeze.
Could you elaborate on the bio/mechanics/physics/chemistry of this? If light can still pass through a frozen retina, what would cause the total loss of vision? Is it because of total neural inactivity?
Reply With Quote
  #22  
Old 01-12-2010, 07:58 PM
Ferret Herder Ferret Herder is offline
Guest
 
Join Date: Mar 2002
Quote:
Originally Posted by xash View Post
Could you elaborate on the bio/mechanics/physics/chemistry of this? If light can still pass through a frozen retina, what would cause the total loss of vision? Is it because of total neural inactivity?
It's not that the light needs to pass through the retina per se - the retina contains the layer of cones and rods in the back of the eye that receives light and translates it into signals, feeding it to the optic nerve and thus into the brain. Freezing the retina would kill those cells, destroying our "optical input."

Last edited by Ferret Herder; 01-12-2010 at 07:59 PM..
Reply With Quote
  #23  
Old 01-12-2010, 08:17 PM
EdwardLost EdwardLost is offline
Guest
 
Join Date: Apr 2009
Debate is pointless - we need some hard data. Someone needs to take one for the team. Unfortunately, it's in the 50's outside here so I can't volunteer.
Reply With Quote
  #24  
Old 01-12-2010, 08:50 PM
user_hostile user_hostile is offline
Charter Member
 
Join Date: May 2002
Location: Near KIAD
Posts: 1,747
Okay, then I'll start with a wimpy bid of -23° F (-30.6° C) outside with no wind. Eyeballs were fine even after 10 minutes; (Location 10 miles north of Nord, Kalaallit Nunaat on the pack ice). Surely, other Dopers have endured much lower temps, right?

Last edited by user_hostile; 01-12-2010 at 08:50 PM.. Reason: Something needed fixing.
Reply With Quote
  #25  
Old 01-12-2010, 09:04 PM
xash xash is offline
Ogministrator
Moderator
 
Join Date: Jan 2001
Location: Palo Alto, CA
Posts: 4,133
Quote:
Originally Posted by EdwardLost View Post
Debate is pointless - we need some hard data. Someone needs to take one for the team. Unfortunately, it's in the 50's outside here so I can't volunteer.
Imagine the chaos if we sent you on this mission.

Search Team Member 1: EdwardLost! EdwardLost!
Search Team Member 2: What?? We lost him? Nooooooo!!!!
Search Team Member 1: No no, we didn't lose him. We're just looking for him
Search Team Member 2: Look! A shiny frozen eyeball! Whose is this?
Search Team Member 1: Maybe it's the one EdwardLost lost
Search Team Member 2: Dude, your voice is echoing
Reply With Quote
  #26  
Old 01-12-2010, 10:44 PM
AHunter3 AHunter3 is offline
Charter Member
 
Join Date: Mar 1999
Location: NY (Manhattan) NY USA
Posts: 16,298
32° Fahrenheit. If you're already dead at the time.

ETA: Hmm, maybe a bit lower than that. Salinity.

Last edited by AHunter3; 01-12-2010 at 10:44 PM..
Reply With Quote
  #27  
Old 01-13-2010, 12:13 AM
Fastidiots Fastidiots is offline
Guest
 
Join Date: Dec 2005
Quote:
Originally Posted by Ferret Herder View Post
It's not that the light needs to pass through the retina per se - the retina contains the layer of cones and rods in the back of the eye that receives light and translates it into signals, feeding it to the optic nerve and thus into the brain. Freezing the retina would kill those cells, destroying our "optical input."
I would imagine rods and cones would stop functioning long before they reached 0*C, as wiki says cell metabolism slows at 30*C.
Reply With Quote
  #28  
Old 01-13-2010, 09:38 AM
Ferret Herder Ferret Herder is offline
Guest
 
Join Date: Mar 2002
Quote:
Originally Posted by tvvat View Post
I would imagine rods and cones would stop functioning long before they reached 0*C, as wiki says cell metabolism slows at 30*C.
Yeah, good point. I was more noting that the retina doesn't merely allow light to go through it, though in a sense that is a description of what it does - rather than passively allowing light through, it actively "passes" light through to the brain, by encoding it into nerve impulses.
Reply With Quote
  #29  
Old 01-13-2010, 11:14 AM
Darwin's Finch Darwin's Finch is offline
Guest
 
Join Date: May 2001
Probably the biggest concern would be the aqueous and vitreous humors freezing, rather than the retina freezing. The aqueous humor (between the lens and the cornea) is mostly water, so were it to freeze, it would expand and damage the cornea, as well as likely displacing the lens. So at best, at that point, you might be able to tell light / dark, but would not see any images.

The vitreous humor, within the eyeball, is more gelatiny, so would require lower temps to freeze. If it were to expand, then you'd basically be looking (heh) at a ruptured eyeball, so no more seeing anything at that point.
Reply With Quote
  #30  
Old 01-13-2010, 02:18 PM
Poysyn Poysyn is offline
Guest
 
Join Date: Jan 2000
I have gone for runs outside when it was -50 (with the windchill, are we including that?).

My eyeballs are fine and unfrozen.

We also have people deployed to Alert, NU, send re-supply trips regularly and have not received any report of frozen eyeballs - or of people getting hypothermia from freezing the cold air.

I think that your eyeballs and lungs can freeze - but the rest of you gives out first and you die.
Reply With Quote
  #31  
Old 01-13-2010, 06:21 PM
Leo Bloom Leo Bloom is offline
Keeping my password unchanged
 
Join Date: Jun 2009
A good link to this question, eyelighting the heat of the vitreous humour, is http://cardhouse.com/berk/science96.htm.

It also deals with how to pee your name in the air and have it turned into peesicles before hitting the ground.
Reply With Quote
  #32  
Old 01-14-2010, 12:30 AM
xash xash is offline
Ogministrator
Moderator
 
Join Date: Jan 2001
Location: Palo Alto, CA
Posts: 4,133
Quote:
Originally Posted by Leo Bloom View Post
A good link to this question, eyelighting the heat of the vitreous humour, is http://cardhouse.com/berk/science96.htm.

It also deals with how to pee your name in the air and have it turned into peesicles before hitting the ground.
Great link! It reads almost as though Cecil wrote that.
Reply With Quote
  #33  
Old 01-24-2011, 08:12 AM
frznIs frznIs is offline
Guest
 
Join Date: Jan 2011
Frozen Eyeballs in the news

A news story in Ottawa, Canada, today claimed that a woman skating on the canal yesterday got frozen eyeballs. I'm going to guess they didn't totally freeze, but only the external layer. It was -25 Celcius and the windchill was -39 Celsius at 9 AM. (for comparson -40 Celsius is -40 Fahrenheit, the scales intersect at that point).

http://www.1310news.com/news/local/a...eless-shelters

also from the reporter:

http://twitter.com/JasonWWhite
Reply With Quote
  #34  
Old 01-24-2011, 08:24 AM
Nava Nava is offline
Guest
 
Join Date: Nov 2004
I do know that I heard my cousin the professional mountain climber say things like "the next time my eyes started freezing..."

The first time he attempted Everest, it was a clear, sunny day and, being the youngest team-member, he was opening the way; he had taken his goggles off and at one point complained about the mist which had been growing. "What mist? " was the answer from his cord-mates - at which point he got a scolding on the lines of "see, we'd told you not to take the goggles off... and that is exactly why!" and got sent back down to camp. It happened again to him at least twice more (both times with goggles on), but never so badly because he was able to recognize the symptoms and turn tail before things got that far.

I have no idea what kind of temperatures that was, but it apparently is common enough. It doesn't cause permanent damage: mountain climbers lose fingers and toes to frostbite with depressing frequency, but eyeballs recover fine once they warm back up.

(And no, I can't ask him, he's a bit dead. Hypothermia in the Himalayas; Iñaki RIP)

Last edited by Nava; 01-24-2011 at 08:27 AM..
Reply With Quote
  #35  
Old 01-24-2011, 08:26 AM
hogarth hogarth is offline
Guest
 
Join Date: Apr 2009
Quote:
Originally Posted by tsukaesugi View Post
This is fiction, and not an answer to the question, but the novel "The Terror" by Dan Simmons, has a very memorable scene where a character's eyeballs freeze.

I immediately thought of that when I saw this thread.
I immediately thought of the story "Wait It Out" by Larry Niven.

EDIT: And shortly thereafter, "Inferno" by Larry Niven and Jerry Pournelle.

Last edited by hogarth; 01-24-2011 at 08:27 AM..
Reply With Quote
  #36  
Old 01-24-2011, 08:58 AM
Machine Elf Machine Elf is offline
Guest
 
Join Date: Feb 2007
Quote:
Originally Posted by cjepson View Post
I hope y'all will pardon the hijack, but this reminded me of something I read in a book on Antarctica. At some extremely low temperature (around -60 F, perhaps?), just breathing the air will cause you to eventually die of hypothermia, no matter how warmly you're dressed.
I just did the math. Short answer? Not true.

Longer answer:

Assume absolutely dry air is inhaled at ambient temp, and that air is then exhaled at body temperature (37C) and 100% relative humidity. Heat is lost from the body due to the warming and humidification of that air.

Assume typical parameters for an adult male at rest: 16 breaths per minute, 1/2-liter tidal volume.

Assume ambient temp of -60C. I calculated heat loss via respiration to be 29 watts. For reference, heat loss (via respiration) when ambient temp is 0C is 19.2 watts, so the heat loss at -60 is only an additional ten watts on top of that. (humidification requires an impressive 13.2 watts, no matter the ambient temperature; this is why the total power requirement doesn't drop that rapidly with increasing ambient temp.)

Various web references indicate that a normal human bean at rest produces 60-90 watts of heat. If your body is perfectly insulated, you'll eventually overheat since you'll only be dumping 29 watts through respiration.
Reply With Quote
Reply



Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 05:10 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@chicagoreader.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Publishers - interested in subscribing to the Straight Dope?
Write to: sdsubscriptions@chicagoreader.com.

Copyright © 2013 Sun-Times Media, LLC.