Frozen Freshlook Colorblends

Scienceguy · #1 (**permalink**) 03-19-2008, 02:22 PM

A friend of mine told me about the time she left a box of contact lenses in her car overnight and the silly things froze. She didn't tell me what she did with them, but I suppose she threw them away.

I'm sure she's not the only person to ever do this. So this is where I want people to go for advice. If you accidentally freeze your contacts, is there any way to salvage them? Is it safe to put them in the microwave to thaw them?

Lollie · #2 (**permalink**) 08-01-2008, 04:12 AM

Lol nah not frozen but once I left some contacts in my case and I didnt want them anymore....few weeks later I took a look at them and all the solution had been absorbed and the contacts had dryed out and were hard like plastic, I got some solution and softly rubbed it into them then left them in solution over night and they were perfect the next day I put one in and it felt fine. Then I threw them away coz they wer ugly lol.
(I know its prolly not the best thing to do and would not suggest it to anyone incase of infection, just thought it was slightly interesting!)

3scompany · #3 (**permalink**) 08-01-2008, 03:34 PM

Quote:

Originally Posted by Lollie

Lol nah not frozen but once I left some contacts in my case and I didnt want them anymore....few weeks later I took a look at them and all the solution had been absorbed and the contacts had dryed out and were hard like plastic, I got some solution and softly rubbed it into them then left them in solution over night and they were perfect the next day I put one in and it felt fine. Then I threw them away coz they wer ugly lol.
(I know its prolly not the best thing to do and would not suggest it to anyone incase of infection, just thought it was slightly interesting!)

You're livin' on the edge, Lollie!

Scienceguy · #4 (**permalink**) 10-14-2009, 02:53 PM

Quote:

Originally Posted by 3scompany

You're livin' on the edge, Lollie!

Yes, indeed. Sounds like Lollie is a risk-taker. I wouldn't even have attempted to wear dried-out contact lenses, even if they did seem soft and comfy.

3scompany · #5 (**permalink**) 11-19-2009, 09:53 AM

Quote:

Originally Posted by Scienceguy

Yes, indeed. Sounds like Lollie is a risk-taker. I wouldn't even have attempted to wear dried-out contact lenses, even if they did seem soft and comfy.

If that would have happened to me, I would have just thrown them out. Lollie said she didn't want them any more, though. I guess she was just curious to see if her "resurrected" contact lenses could be worn at all. Truly living on the edge.

Scienceguy · #6 (**permalink**) 12-10-2009, 01:55 PM

Quote:

Originally Posted by 3scompany

If that would have happened to me, I would have just thrown them out. Lollie said she didn't want them any more, though. I guess she was just curious to see if her "resurrected" contact lenses could be worn at all. Truly living on the edge.

Once again it's one of those stories where things can be okay or go horribly wrong. If someone were to ask Lollie why she was trying to rewet her dried out contacts and she said "I want to see if they're safe to wear" her friend might well have a very valid question.

"What if they're not?"

Don't try this at home.

sspye · #7 (**permalink**) 01-01-2010, 01:15 PM

OK, but.....what if.....

I have contacts due to arrive at my house tomorrow. My letter carrier arrives at my house early in the morning. We are having freezing temps here and I have to work until 6:30pm. I don't have any neighbor's. We live in a rural area. Will they freeze if left on my porch?

3scompany · #8 (**permalink**) 01-26-2010, 01:22 PM

Quote:

Originally Posted by sspye

OK, but.....what if.....

I have contacts due to arrive at my house tomorrow. My letter carrier arrives at my house early in the morning. We are having freezing temps here and I have to work until 6:30pm. I don't have any neighbors. We live in a rural area. Will they freeze if left on my porch?

Sorry the Lens 101 Army couldn't respond to your question before you went home that day. Did your contacts freeze on your porch as you'd feared?

Knotlob · #9 (**permalink**) 01-26-2010, 01:53 PM

Quote:

Originally Posted by 3scompany

Sorry the Lens 101 Army couldn't respond to your question before you went home that day. Did your contacts freeze on your porch as you'd feared?

I'd be interested to know the answer also. I haven't found any warnings in contact lens packs which specifically warn against freezing.

The problem is that the soft contacts contain water and if it was cold enough, then the lens solution/saline, etc. will freeze and it will expand as ice is formed. Probably shatter the case, but I do wonder about the lenses themselves. Could try it with a single daily disposable lens and see what happens. If it is trashed, then no big deal and lesson learnt.

knotlob

AllyCat · #10 (**permalink**) 01-26-2010, 02:19 PM

Quote:

Originally Posted by Knotlob

I'd be interested to know the answer also. I haven't found any warnings in Contact lens packs which specifically warn against freezing.

The problem is that the soft contacts contain water and if it was cold enough, then the lens solution/saline, etc. will freeze and it will expand as ice is formed. Probably shatter the case, but I do wonder about the lenses themselves. Could try it with a single daily disposable lens and see what happens. If it is trashed, then no big deal and lesson learnt.

knotlob

Here's the tricky part. Salt water has a lower freezing temperature than fresh water. I found this at a website called madsci.org.

"Salt lowers the temperature at which water freezes and melts. Pure water, H2O, freezes . . . at 0°C (32°F). But the more 'salt' . . . in water, the lower its freezing point. For example, seawater, which has approximately 3500 parts per million 'salt' . . . will freeze . . . at -2.2°C. A water with extreme salinity such as very salty lake waters at Death Valley, California (approximately 300,000 parts per million 'salt') may freeze . . . at temperatures as low as -20 - -30°C!
Because salt lowers the freezing point depression, it is added to icy roads in order to melt the ice."

Shouldn't the saline solution that contact lenses are packed in resist freezing?

It probably won't make that big of a difference, but it does make a difference, right?

Knotlob · #11 (**permalink**) 01-26-2010, 02:52 PM

Quote:

Originally Posted by AllyCat

Here's the tricky part. Salt water has a lower freezing temperature than fresh water. I found this at a website called madsci.org.

"Salt lowers the temperature at which water freezes and melts. Pure water, H2O, freezes . . . at 0°C (32°F). But the more 'salt' . . . in water, the lower its freezing point. For example, seawater, which has approximately 3500 parts per million 'salt' . . . will freeze . . . at -2.2°C. A water with extreme salinity such as very salty lake waters at Death Valley, California (approximately 300,000 parts per million 'salt') may freeze . . . at temperatures as low as -20 - -30°C!
Because salt lowers the freezing point depression, it is added to icy roads in order to melt the ice."

Shouldn't the saline solution that contact lenses are packed in resist freezing?

It probably won't make that big of a difference, but it does make a difference, right?

Hello AllyCat

Yes, you are correct that salt added to water depresses the freezing point. Time for some chemistry perhaps?

The lenses would probably be stored in something like saline (NaCl salt solution) and this will be balanced for the same isotonic concentration as your body. This is 0.91% w/v NaCl, which is 9.1g in 1000 litres of water (9,100 parts/million). So it is a bit more concentrated than sea water and will, therefore, freeze at a lower temperature.

I think temperatures in parts of the US/Canada can get down quite low sometimes (it was -15 Deg C/+5 Deg F) here in Hamburg this morning, but that is just a little unusual - thankfully.

So if your friendly postman decided to leave the lens delivery on your doorstep in the depth of winter, they would probably freeze.

In answer to ScienceGuy's original question, no I wouldn't microwave them - you could easily over heat them. Just let them thaw out naturally - it wouldn't take long in a normal heated house.

knotlob

Droopy · #12 (**permalink**) 01-26-2010, 03:23 PM

Quote:

Originally Posted by Knotlob

Hello AllyCat

Yes, you are correct that salt added to water depresses the freezing point. Time for some chemistry perhaps?

The lenses would probably be stored in something like saline (NaCl salt solution) and this will be balanced for the same isotonic concentration as your body. This is 0.91% w/v NaCl, which is 9.1g in 1000 litres of water (9,100 parts/million). So it is a bit more concentrated than sea water and will, therefore, freeze at a lower temperature.

I think temperatures in parts of the US/Canada can get down quite low sometimes (it was -15 Deg C/+5 Deg F) here in Hamburg this morning, but that is just a little unusual - thankfully.knotlob

I love it when you talk like that!

Thank you for that detailed explanation. I was kind of surprised when you said that saline solution is "a bit more concentrated than sea water." I was about to reply with "They probably won't freeze because saline solution isn't nearly as salty as the sea water in your example."
I've never tasted saline solution, but I have tasted seawater, and it's very salty. Is the saline solution that is used to store contact lenses even more salty than that?

Oh, and by the way, this morning in the Midwestern United States where I am, it was about 9 deg C. (I needed to find a metric converter just for you, Knotlob. Say what you will about Ugly Americans.

)

Knotlob · #13 (**permalink**) 01-26-2010, 03:36 PM

Quote:

Originally Posted by Droopy

I love it when you talk like that!

Thank you for that detailed explanation. I was kind of surprised when you said that saline solution is "a bit more concentrated than sea water." I was about to reply with "They probably won't freeze because saline solution isn't nearly as salty as the sea water in your example."
I've never tasted saline solution, but I have tasted seawater, and it's very salty. Is the saline solution that is used to store contact lenses even more salty than that?

Oh, and by the way, this morning in the Midwestern United States where I am, it was about 9 deg C. (I needed to find a metric converter just for you, Knotlob. Say what you will about Ugly Americans.

)

Hi Droopy

If you had asked me if isotonic saline was saltier than sea water, I would probably have said no, but I took the isotonic data from various sources some time ago when I wanted to check a solution make up.

Just checked a bottle of lens saline solution and that is 0.75% w/v, so a little less, but still the same ball park.

Mid West US, 9 Deg C seems quite warm for this time of year. No cross country skiing for you then

knotlob

Droopy · #14 (**permalink**) 01-26-2010, 03:44 PM

Quote:

Originally Posted by Knotlob

Hi Droopy

If you had asked me if isotonic saline was saltier than sea water, I would probably have said no, but I took the isotonic data from various sources some time ago when I wanted to check a solution make up.

Just checked a bottle of lens saline solution and that is 0.75% w/v, so a little less, but still the same ball park.

Mid West US, 9 Deg C seems quite warm for this time of year. No cross country skiing for you then

knotlob

Yes, I suppose you're right. I checked on line and it seems that around these parts the average temperature for January is about -5 deg. C. In July it's about 24. I miss those days.

No cross country skiing. The snow is melting.

Thanks for explaining about isotonic saline and what an actual bottle said.

3scompany · #15 (**permalink**) 02-09-2010, 12:14 PM

Quote:

Originally Posted by Knotlob

Hi Droopy

If you had asked me if isotonic saline was saltier than sea water, I would probably have said no, but I took the isotonic data from various sources some time ago when I wanted to check a solution make up.

Just checked a bottle of lens saline solution and that is 0.75% w/v, so a little less, but still the same ball park.

Mid West US, 9 Deg C seems quite warm for this time of year. No cross country skiing for you then

knotlob

Do you mean to tell me that saline solution is roughly as salty as sea water? How comes it stings so much when I get sea water in my eyes? (Not that I've been to the ocean in the last several years.)

Knotlob · #16 (**permalink**) 02-09-2010, 02:38 PM

Quote:

Originally Posted by 3scompany

Do you mean to tell me that saline solution is roughly as salty as sea water? How comes it stings so much when I get sea water in my eyes? (Not that I've been to the ocean in the last several years.)

The saline solution is more than double the NaCl concentration of salt water according to AllyCat's figures for sea water. I don't know why sea water should sting and isotonic saline does not.

However, remember that sea water contains many many salts, not just sodium chloride, so the overall salt concentration will perhaps be much higher than isotonic saline solution. That would probably cause stinging, or possibly one of the other salts (not to mention suspended sand, algae, etc. in the sea water).

It's a while since I swam in proper sea water. In Northern Germany most people go to the Baltic Sea, which is very brackish and has the reputation for being heavily polluted - and that's before this week's story about the Ruskies dumping nuclear waste into the sea in Swedish waters during the 1990's.

knotlob

Scienceguy · #17 (**permalink**) 02-24-2010, 03:31 PM

Quote:

Originally Posted by Knotlob

The saline solution is more than double the NaCl concentration of salt water according to AllyCat's figures for sea water. I don't know why sea water should sting and isotonic saline does not.

However, remember that sea water contains many many salts, not just sodium chloride, so the overall salt concentration will perhaps be much higher than isotonic saline solution. That would probably cause stinging, or possibly one of the other salts (not to mention suspended sand, algae, etc. in the sea water).

It's a while since I swam in proper sea water. In Northern Germany most people go to the Baltic Sea, which is very brackish and has the reputation for being heavily polluted - and that's before this week's story about the Ruskies dumping nuclear waste into the sea in Swedish waters during the 1990's.

knotlob

Thanks for the post, Knotlob. I bet there's more than NaCl in sea water as well.

Knotlob · #18 (**permalink**) 02-24-2010, 05:00 PM

Quote:

Originally Posted by Scienceguy

Thanks for the post, Knotlob. I bet there's more than NaCl in sea water as well.

Further info out of idle curiosity.

http://en.wikipedia.org/wiki/Seawater

Wikipedia states that sea water averages 3.5% salinity, i.e. 35 parts/thousand. So sea water contains 35g of salt NaCl in 1000g or 1 litre of sea water.

(3.5% salinity is also the figure in other publications:

http://www.seafriends.org.nz/oceano/seawater.htm

http://www.marinebio.net/marinescience/02ocean/swcomposition.htm)

N.B. This is 10 times higher than the post by Allycat states 3500 ppm (i.e. 3.5 parts/thousand). Sea water is therefore about 5 times more salty than iso-tonic lens solution and this fits in with people's observation/experience of tasting sea water!

(I had a look at the madsci.org website and generally it says the salinity of sea water is 35g/litre water, but I eventually found the quote that Allycat has presumably cut and pasted from that site. Presumably it's a typo on that site):

http://www.madsci.org/posts/archives/mar98/890115623.Ch.r.html

Getting back to the original question, the iso-tonic saline will likely freeze at about -0.4 deg C:

(http://www.madsci.org/posts/archives/feb98/888588209.Es.r.html)

knotlob

Klingons4Peace · #19 (**permalink**) 02-25-2010, 09:35 AM

Quote:

Originally Posted by Knotlob

Further info out of idle curiosity.

http://en.wikipedia.org/wiki/Seawater

Wikipedia states that sea water averages 3.5% salinity, i.e. 35 parts/thousand. So sea water contains 35g of salt NaCl in 1000g or 1 litre of sea water.

(3.5% salinity is also the figure in other publications:

http://www.seafriends.org.nz/oceano/seawater.htm

http://www.marinebio.net/marinescience/02ocean/swcomposition.htm)

N.B. This is 10 times higher than the post by Allycat states 3500 ppm (i.e. 3.5 parts/thousand). Sea water is therefore about 5 times more salty than iso-tonic lens solution and this fits in with people's observation/experience of tasting sea water!

knotlob

Looks like you put your idle curiosity to good use, knotlob.

Scienceguy · #20 (**permalink**) 02-26-2010, 11:57 AM

Quote:

Originally Posted by Knotlob

Further info out of idle curiosity.

http://en.wikipedia.org/wiki/Seawater

Wikipedia states that sea water averages 3.5% salinity, i.e. 35 parts/thousand. So sea water contains 35g of salt NaCl in 1000g or 1 litre of sea water.

(3.5% salinity is also the figure in other publications:

http://www.seafriends.org.nz/oceano/seawater.htm

http://www.marinebio.net/marinescience/02ocean/swcomposition.htm)

N.B. This is 10 times higher than the post by Allycat states 3500 ppm (i.e. 3.5 parts/thousand). Sea water is therefore about 5 times more salty than iso-tonic lens solution and this fits in with people's observation/experience of tasting sea water!

(I had a look at the madsci.org website and generally it says the salinity of sea water is 35g/litre water, but I eventually found the quote that Allycat has presumably cut and pasted from that site. Presumably it's a typo on that site)

knotlob

Looks like madsci.org needs to do a little recalculating. Thanks for catching that, knotlob. I heard about a rocket that was supposed to go to Venus but the silly thing wound up on the ocean floor on terra . . . well, maybe not firma, but it lever left the Earth's atmosphere. The reason was that a minus sign was apparently in the program where it shouldn't have been.

Look here: "MARINER 1, the first U.S. attempt to send a spacecraft to Venus, failed
minutes after launch in 1962. The guidance instructions from the ground
stopped reaching the rocket due to a problem with its antenna, so the
onboard computer took control. However, there turned out to be a bug in
the guidance software, and the rocket promptly went off course, so the
Range Safety Officer destroyed it. Although the bug is sometimes claimed
to have been an incorrect FORTRAN DO statement, it was actually a
transcription error in which the bar (indicating smoothing) was omitted
from the expression "R-dot-bar sub n" (nth smoothed value of derivative
of radius). This error led the software to treat normal minor variations
of velocity as if they were serious, leading to incorrect compensation."

Remember to dot your i's and cross your t's, kids.

AllyCat · #21 (**permalink**) 03-16-2010, 12:09 PM

Quote:

Originally Posted by Scienceguy

Looks like madsci.org needs to do a little recalculating. Thanks for catching that, knotlob. I heard about a rocket that was supposed to go to Venus but the silly thing wound up on the ocean floor on terra . . . well, maybe not firma, but it lever left the Earth's atmosphere. The reason was that a minus sign was apparently in the program where it shouldn't have been.

Look here: "MARINER 1, the first U.S. attempt to send a spacecraft to Venus, failed
minutes after launch in 1962. The guidance instructions from the ground
stopped reaching the rocket due to a problem with its antenna, so the
onboard computer took control. However, there turned out to be a bug in
the guidance software, and the rocket promptly went off course, so the
Range Safety Officer destroyed it. Although the bug is sometimes claimed
to have been an incorrect FORTRAN DO statement, it was actually a
transcription error in which the bar (indicating smoothing) was omitted
from the expression "R-dot-bar sub n" (nth smoothed value of derivative
of radius). This error led the software to treat normal minor variations
of velocity as if they were serious, leading to incorrect compensation."

Remember to dot your i's and cross your t's, kids.

Thanks for that information, scienceguy. It was interesting, if a bit hard to follow. My eyes began to glaze over when I read that "nth smoothed value of derivative
of radius" part.