Why Do Contact Lenses Have "Time Limits"?

Jesterhester · #1 (**permalink**) 02-15-2008, 01:08 PM

This is a very basic question that eye doctors probably get asked every day, but I haven't seen if here in Lens 101 yet. How come you can only wear daily contact lenses for one day? Do they become fragile and rip after that or what? Why are monthlies only good for 30 wears,and so on?

harrychiling · #2 (**permalink**) 02-16-2008, 09:24 PM

That's a great question, the daily lenses don't have any surface treatments applied to them, which means that they will build deposits (gunk, proteins, lipids, etc.) on the lens. They are basically processed less becuase they are meant to be thrown out at the end of the day. Other lenses 2 week and monthly have been treated to provide better deposit resistance or are made of materials that provide better depost resitance than dailies. Depending on the person on their wear I have seen patients that wear a two week lens monthly and have next to no depsoits on the lens and I have also seen patients that wear those same two week lenses and have deposits the first day or two. We are all built differently and the wear time is really a great way of giving patients a good idea of when to get rid of their lenses, but I have often metioned to patients that if they are a casual wearer then 2 weeks or 14 days is a good timeline for a two week disposable, but never go beyond the two week period, because the additional proteins can and will effect your comfort and ultimately your ocular health.

unclebuck · #3 (**permalink**) 06-11-2008, 05:12 PM

Quote:

Originally Posted by harrychiling

That's a great question, the daily lenses don't have any surface treatments applied to them, which means that they will build deposits (gunk, proteins, lipids, etc.) on the lens. They are basically processed less because they are meant to be thrown out at the end of the day. Other lenses 2 week and monthly have been treated to provide better deposit resistance or are made of materials that provide better deposit resistance than dailies. Depending on the person on their wear I have seen patients that wear a two week lens monthly and have next to no deposits on the lens and I have also seen patients that wear those same two week lenses and have deposits the first day or two. . .

What a great answer. Thanks.

megane_ko · #4 (**permalink**) 02-22-2009, 04:20 AM

How do you know if there are deposits on the lens?

chemist · #5 (**permalink**) 02-22-2009, 09:10 AM

what is not mentioned is that it is easy to buy weekly enzymatic cleaners that will dissolve the buildup.

note also that no mention is made of increased susceptibility to infections - which is correct.

I've been using a hydrogen peroxide based cleaner and a product called Unizyme on a weekly basis to extend the contact lens wear times.

I have no connection with any manufacturer in the contact lens business

Ricardo · #6 (**permalink**) 02-23-2009, 09:55 AM

Quote:

Originally Posted by chemist

what is not mentioned is that it is easy to buy weekly enzymatic cleaners that will dissolve the buildup.

I have a question - Do the enzymatic cleaners that dissolve the buildup have an effect on the contact lenses themselves, as in breaking down the material?

chemist · #7 (**permalink**) 02-23-2009, 01:05 PM

there is no lens degradation from enzyme cleaners

lovian05 · #8 (**permalink**) 02-24-2009, 07:30 AM

at first im wondering why do contact lenses has an expiration...now i came to realize that everything has an expiration, nothing last forever. lol!

anyway, it's simply because it will irretate our eyes...

Jesterhester · #9 (**permalink**) 04-28-2009, 12:40 PM

Quote:

Originally Posted by harrychiling

That's a great question, the daily lenses don't have any surface treatments applied to them, which means that they will build deposits (gunk, proteins, lipids, etc.) on the lens. They are basically processed less because they are meant to be thrown out at the end of the day. Other lenses 2 week and monthly have been treated to provide better deposit resistance or are made of materials that provide better deposit resistance than dailies. Depending on the person on their wear I have seen patients that wear a two week lens monthly and have next to no deposits on the lens and I have also seen patients that wear those same two week lenses and have deposits the first day or two. We are all built differently and the wear time is really a great way of giving patients a good idea of when to get rid of their lenses, but I have often mentioned to patients that if they are a casual wearer then 2 weeks or 14 days is a good time line for a two week disposable, but never go beyond the two week period, because the additional proteins can and will effect your comfort and ultimately your ocular health.

Thank you for your time, harrychilling. So it seems like it's all about deposits, then, isn't it?

You said that "2 weeks or 14 days is a good time line for a two week disposable," but I thought I heard that it's more about how many times you wear the lenses rather than the length of time. If you only put your contacts in every other day, can you wear monthly lenses for two months, in other words, you put them in and take them out thirty times before you're done with them?

Anthanxan · #10 (**permalink**) 08-02-2010, 10:17 AM

Quote:

Originally Posted by Jesterhester

Thank you for your time, harrychilling. So it seems like it's all about deposits, then, isn't it?

You said that "2 weeks or 14 days is a good time line for a two week disposable," but I thought I heard that it's more about how many times you wear the lenses rather than the length of time. If you only put your contacts in every other day, can you wear monthly lenses for two months, in other words, you put them in and take them out thirty times before you're done with them?

I've heard the same thing, Jesterhester. Daily disposable contact lenses can only be put in your eyes once. So if you wear your contacts for say, three hours, then take them out for some reason, they're done, right? You can't put them back in?

unclebuck · #11 (**permalink**) 08-10-2010, 03:26 PM

Quote:

Originally Posted by Anthanxan

I've heard the same thing, Jesterhester. Daily disposable contact lenses can only be put in your eyes once. So if you wear your contacts for say, three hours, then take them out for some reason, they're done, right? You can't put them back in?

I'm not an expert, but that's my understanding, yes.

Jesterhester · #12 (**permalink**) 08-12-2010, 12:47 PM

Quote:

Originally Posted by Anthanxan

I've heard the same thing, Jesterhester. Daily disposable contact lenses can only be put in your eyes once. So if you wear your contacts for say, three hours, then take them out for some reason, they're done, right? You can't put them back in?

I think so, yes.

Knotlob · #13 (**permalink**) 08-12-2010, 01:34 PM

Quote:

Originally Posted by Jesterhester

I think so, yes.

I very seldom wear daily disposables, but if I got some dirt on the lens or the lens became dry, then I would take it out and give it a quick rinse with some contact lens solution, before putting it back in the eye.

It's no problem provided you have the contact lens solution (which you normally would not have for Daily Disposables).

Only thing you need to be careful with, is the relative fragility of daily disposable lenses.

knotlob

Ordersixtysix · #14 (**permalink**) 08-12-2010, 02:46 PM

Quote:

Originally Posted by Knotlob

I very seldom wear daily disposables, but if I got some dirt on the lens or the lens became dry, then I would take it out and give it a quick rinse with some contact lens solution, before putting it back in the eye.

It's no problem provided you have the contact lens solution (which you normally would not have for Daily Disposables).

Only thing you need to be careful with, is the relative fragility of daily disposable lenses.

knotlob

Thanks for your personal experience, Knotlob. Those daily disposable contacts seem pretty thin to me. Is it fairly simple to handle them without damaging them? Can you take them out two or three times without ripping one of them?

Knotlob · #15 (**permalink**) 08-12-2010, 03:35 PM

Quote:

Originally Posted by Ordersixtysix

Thanks for your personal experience, Knotlob. Those daily disposable contacts seem pretty thin to me. Is it fairly simple to handle them without damaging them? Can you take them out two or three times without ripping one of them?

Well that depends on the lens I think.

I did wear (but only as an experiment) SofLens Daily Disposables for several weeks without any problem (daytime only and disinfect at night). I don't wear daily lenses usually.

Then I tried Biofinity (monthly lens) and managed to damage that after only 6 days - peripheral damage, but that was probably the lens case I was using.

You can, with care, fit the daily disposable lens about three times in the same day. Obviously it helps if you are experienced and don't have to poke about in your eye to get the lens out, which would probably damage the lens quite quickly and make your eyes red, etc.

You also need to watch the condition of your finger nails, etc.

knotlob

Walkaway · #16 (**permalink**) 08-12-2010, 04:09 PM

Quote:

Originally Posted by Knotlob

Well that depends on the lens I think.

I did wear (but only as an experiment) SofLens Daily Disposables for several weeks without any problem (daytime only and disinfect at night). I don't wear daily lenses usually.

Then I tried Biofinity (monthly lens) and managed to damage that after only 6 days - peripheral damage, but that was probably the lens case I was using.

You can, with care, fit the daily disposable lens about three times in the same day. Obviously it helps if you are experienced and don't have to poke about in your eye to get the lens out, which would probably damage the lens quite quickly and make your eyes red, etc.

You also need to watch the condition of your finger nails, etc.

knotlob

I guess there are a lot more factors to think about besides the thickness of the lens, aren't there?

Jesterhester · #17 (**permalink**) 08-19-2010, 04:17 PM

Quote:

Originally Posted by Knotlob

I very seldom wear daily disposables, but if I got some dirt on the lens or the lens became dry, then I would take it out and give it a quick rinse with some contact lens solution, before putting it back in the eye.

It's no problem provided you have the contact lens solution (which you normally would not have for Daily Disposables).

Only thing you need to be careful with, is the relative fragility of daily disposable lenses.

knotlob

"Chemist" said that enzymatic cleaners do not "degrade" daily disposable contact lenses, and I can hear the question forming in many a Lens 101 surfer's mind: Why not just soak them overnight and wear them again?

Knotlob · #18 (**permalink**) 08-19-2010, 05:08 PM

Quote:

Originally Posted by Jesterhester

"Chemist" said that enzymatic cleaners do not "degrade" daily disposable contact lenses, and I can hear the question forming in many a Lens 101 surfer's mind: Why not just soak them overnight and wear them again?

Enzymatic cleaners are designed normally to remove protein deposits. You don't need these relatively expensive cleaners just to remove dirt from a lens dropped on the floor.

Daily disposables probably could be worn more than once but they are usually more susceptible to mechanical handling damage. For many people the benefit of the Daily Disposable is the convenience of not having to clean the lenses anyway, or if they have problems with heavy protein deposits, then Daily Disposables worn once will be better.

knotlob

Tradecade · #19 (**permalink**) 08-20-2010, 11:52 AM

Quote:

Originally Posted by Knotlob

Enzymatic cleaners are designed normally to remove protein deposits. You don't need these relatively expensive cleaners just to remove dirt from a lens dropped on the floor.

Daily disposables probably could be worn more than once but they are usually more susceptible to mechanical handling damage. For many people the benefit of the Daily Disposable is the convenience of not having to clean the lenses anyway, or if they have problems with heavy protein deposits, then Daily Disposables worn once will be better.

knotlob

So many good reasons to wear daily disposable contact lenses. Thank you knotlob.

unclebuck · #20 (**permalink**) 09-23-2010, 05:35 PM

Quote:

Originally Posted by chemist

what is not mentioned is that it is easy to buy weekly enzymatic cleaners that will dissolve the buildup.

note also that no mention is made of increased susceptibility to infections - which is correct.

Why would wearing daily disposable contact lenses make you more likely to get an infection? As long as you clean them they should be fine, right?

Knotlob · #21 (**permalink**) 09-23-2010, 06:00 PM

Quote:

Originally Posted by unclebuck

Why would wearing daily disposable contact lenses make you more likely to get an infection? As long as you clean them they should be fine, right?

Eye Care Professionals (ECP) seem to favour Daily Disposable lenses BECAUSE they are more healthy. There is less of a potential problem with protein build up, you don't have to worry about cleaning them (especially with teenagers or younger) and if you loose one, then they are cheap/lens to replace.

One problem with people wearing a Daily Lens for longer than a day is that the ECP will probably NOT have taught them anything about cleaning the lenses at night - you're going to throw them away, right?

If you are an experienced contact lens wearer and are prepared to properly disinfect the lenses nightly, preferably with a peroxide based system and perhaps use enzyme tablets, then you shouldn't get an infection. But then you may as well wear a weekly or biweekly lens made from silicone hydrogel and get some of the newer material benefits, such as higher oxygen permeability.

knotlob

Knotlob · #22 (**permalink**) 09-23-2010, 06:07 PM

Quote:

Originally Posted by lovian05

at first im wondering why do contact lenses has an expiration...now i came to realize that everything has an expiration, nothing last forever. lol!

anyway, it's simply because it will irretate our eyes...

I don't think this question was directly answered but it was asked a long time ago.

Expiry dates are usually about 4 years after packaging. The soft lenses are stored in a saline, pH buffered solution, which should be sterile. The four year time limit is considered to be the cut off time when the seals will have degraded and the contact lens may no longer be sterile.

You would get some clues if it were non sterile, such as cloudy or bad smelling liquid. If the liquid and lenses looked normal, but the expiry date was passed, you could sterilise the lenses in contact lens peroxide cleaner. Naturally, if the lenses were cheap (daily disposables) then you probably wouldn't bother and just throw them away.

knotlob

Eyeofharmony · #23 (**permalink**) 09-24-2010, 11:34 AM

Quote:

Originally Posted by Knotlob

Enzymatic cleaners are designed normally to remove protein deposits. You don't need these relatively expensive cleaners just to remove dirt from a lens dropped on the floor.

Daily disposables probably could be worn more than once but they are usually more susceptible to mechanical handling damage. For many people the benefit of the Daily Disposable is the convenience of not having to clean the lenses anyway, or if they have problems with heavy protein deposits, then Daily Disposables worn once will be better.

knotlob

So if you're going to clean them and wear them again anyway, why get daily lenses, right? Is there a financial gain? People will do anything for money.

lurker2010 · #24 (**permalink**) 09-25-2010, 10:41 AM

Nice picture of a $20 bill. Doesn't do anything to advance the discussion. A patient who wears daily disposable lenses for 2 or 3 consecutive days (taking them out at night and properly disinfecting them) will save more then $20.

You said "people will do anything for money" Are you referring to customers who save money be using daily disposable lenses for more then a single days or are you talking about lens manufacturers who market the same, or substantially the same lens, with different replacement schedules at different prices?

Are you talking about the company that is subject to investigation by California consumer affairs and class action law suits? The company claimed their multip purpose product was "new and unique". The identical product is sold by COSTCO, under the Kirkland brand name, at a lower price. "Do anything for money" certainly applies.

PTUser · #25 (**permalink**) 09-27-2010, 10:30 AM

Quote:

Originally Posted by lurker2010

Nice picture of a $20 bill. Doesn't do anything to advance the discussion. A patient who wears daily disposable lenses for 2 or 3 consecutive days (taking them out at night and properly disinfecting them) will save more then $20.

You said "people will do anything for money" Are you referring to customers who save money be using daily disposable lenses for more then a single days or are you talking about lens manufacturers who market the same, or substantially the same lens, with different replacement schedules at different prices?

Are you talking about the company that is subject to investigation by California consumer affairs and class action law suits? The company claimed their multip purpose product was "new and unique". The identical product is sold by COSTCO, under the Kirkland brand name, at a lower price. "Do anything for money" certainly applies.

I can't tell you what's going on in EyeofHarmony's head, but I'm guessing the picture combines the ideas of "love" and "money" in a unique way.

The question seems to be about people who buy lenses that clearly say "daily disposable" on the box, but do not dispose of them daily. EyeofHarmony is likely wondering why people reuse daily disposable lenses when you can just buy weekly or monthly lenses that can safely be worn at night. It must be cheaper to buy daily lenses and then try to wear them for two or three days, otherwise, why bother? Right?

lurker2010 · #26 (**permalink**) 09-27-2010, 10:38 AM

NO--Taking a daily lens out before you go to sleep, disinfect the lens then wear it the next day is not the same as wearing a lens overnight extended wear.

Many lenses are not safe to wear when you sleep. Many doctors think most patients are better off not sleeping in a lens, even if that lens is approved for overnight wear.

The point of the threads is suggesting that, at least in the past, daily disposable lenses were the same (or substantially the same) as 14 day lenses. A lens that's approved for overnight wear is not equivalent to a lens that's not intended for overnight wear.

Quote:

Originally Posted by PTUser

EyeofHarmony is likely wondering why people reuse daily disposable lenses when you can just buy weekly or monthly lenses that can safely be worn at night. It must be cheaper to buy daily lenses and then try to wear them for two or three days, otherwise, why bother? Right?

ReTina · #27 (**permalink**) 09-27-2010, 12:12 PM

Quote:

Originally Posted by lurker2010

NO--Taking a daily lens out before you go to sleep, disinfect the lens then wear it the next day is not the same as wearing a lens overnight extended wear.

Many lenses are not safe to wear when you sleep. Many doctors think most patients are better off not sleeping in a lens, even if that lens is approved for overnight wear.

The point of the threads is suggesting that, at least in the past, daily disposable lenses were the same (or substantially the same) as 14 day lenses. A lens that's approved for overnight wear is not equivalent to a lens that's not intended for overnight wear.

So you're saying that some people clean their daily disposable lenses and then wear them again? That's crazy. Why would anyone do that? I would think that people would get a clue when they see the word "disposable" on the box. The word "daily" might offer a hint as well. How much clearer do they have to be?

"I wonder how long I should wear these daily disposable contact lenses? I have no clue. I wish I had some information that would make it clear to me."

lurker2010 · #28 (**permalink**) 09-27-2010, 12:31 PM

Some people think it's crazy to throw out a perfectly good lens after only one wearing.

Some companies marketed the identical lens as both daily disposable and as planned replacement lenses.

Some manufacturers still file a lens with the FDA for use as a daily lens and for planned replacement. The eye practitioner decides on the wear schedule and disinfection regime.

Some patients can safely wear a daily lens for more then one day.

Patients who wear daily disposable lenses don't need to bother with cleaning solutions and cases. Properly cleaning and disinfecting a daily use lens negates the advantage of using a daily lens.

Having to buy and use Clearcare and saline kind of defeats one of the advantages of using a daily disposable lens.

Daily disposable lenses tend to rip when subjected to the kind of rub cleaning that's necessary to maintain the lenses for more then 2 or 3 days.

Some patients, and even some eye doctors, consider the manufactures labeling more of a suggestion. I'd never get more then about 10 days out of a 14 day lens or 60 days out of a 3 month lens.

Some people can safely wear a lens for more then suggested by the mfg. Some people can't even wear them for the suggested wear schedule.

There is no substitute for examining your lens for rips, small tears and deposits that you can't remove.

dragongirl81 · #29 (**permalink**) 09-27-2010, 12:38 PM

Quote:

Originally Posted by lurker2010

Some people think it's crazy to throw out a perfectly good lens after only one wearing.

Some companies marketed the identical lens as both daily disposable and as planned replacement lenses.

Some manufacturers still file a lens with the FDA for use as a daily lens and for planned replacement. The eye practitioner decides on the wear schedule and disinfection regime.

Some patients can safely wear a daily lens for more then one day.

Patients who wear daily disposable lenses don't need to bother with cleaning solutions and cases. Properly cleaning and disinfecting a daily use lens negates the advantage of using a daily lens.

Having to buy and use Clearcare and saline kind of defeats one of the advantages of using a daily disposable lens.

Daily disposable lenses tend to rip when subjected to the kind of rub cleaning that's necessary to maintain the lenses for more then 2 or 3 days.

Some patients, and even some eye doctors, consider the manufactures labeling more of a suggestion. I'd never get more then about 10 days out of a 14 day lens or 60 days out of a 3 month lens.

Some people can safely wear a lens for more then suggested by the mfg. Some people can't even wear them for the suggested wear schedule.

There is no substitute for examining your lens for rips, small tears and deposits that you can't remove.

Wow. That's pretty much everything I need to know about contacts in one posting. Thanks, Lurker.

I've been around this site a long time and it's kind of a pet peeve of mine when people decide to call themselves "experts" and tell people to wear their contacts as long as they want. "It doesn't matter," they say. "They're all the same anyway."

I agree with you that you need to let your eye care professional decide how long you can wear your "daily" lenses. Whatever kind of lenses you wear, there's no better way to know how long to wear your contacts than asking your doctor.

lurker2010 · #30 (**permalink**) 09-27-2010, 12:44 PM

Quote:

Originally Posted by dragongirl81

I've been around this site a long time and it's kind of a pet peeve of mine when people decide to call themselves "experts" and tell people to wear their contacts as long as they want. "It doesn't matter," they say. "They're all the same anyway."

It's a pete peeve of mine when people call themselves "experts" and tell people the should never disinfect a daily lens and wear it a second or third day. When people use bogus analogies such as comparing daily disposable lenses to paper plates and 14 day lenses to fine china.

It goes both ways. A lot of posters are short on facts and long on bogus pictures and analogies.

Knotlob · #31 (**permalink**) 09-27-2010, 12:46 PM

Quote:

Originally Posted by dragongirl81

Wow. That's pretty much everything I need to know about contacts in one posting. Thanks, Lurker.

I've been around this site a long time and it's kind of a pet peeve of mine when people decide to call themselves "experts" and tell people to wear their contacts as long as they want. "It doesn't matter," they say. "They're all the same anyway."

I agree with you that you need to let your eye care professional decide how long you can wear your "daily" lenses. Whatever kind of lenses you wear, there's no better way to know how long to wear your contacts than asking your doctor.

Thanks Lurker 2010, that's a comprehensive posting.

I think if you do ask your doctor about wearing a Daily Disposable for longer than a day, almost all will say one day only. Very few will stick the head above the parapet and say longer, unless they know you extremely well.

knotlob

dragongirl81 · #32 (**permalink**) 09-27-2010, 01:05 PM

Quote:

Originally Posted by lurker2010

It's a pete peeve of mine when people call themselves "experts" and tell people the should never disinfect a daily lens and wear it a second or third day. When people use bogus analogies such as comparing daily disposable lenses to paper plates and 14 day lenses to fine china.

It goes both ways. A lot of posters are short on facts and long on bogus pictures and analogies.

Lurker2010, I've noticed that you've been crabbing about that "paper plate analogy" for almost a year now. I have two questions for you:

1. What's wrong with it?
2. Why won't you let it go? Even if it is a "bogus analogy," nobody mentioned paper plates in this thread, but you had to bring it up again.

Knotlob, you're a pretty sharp guy, are you familiar with this "paper plate analogy"? What do you think about it?

lurker2010 · #33 (**permalink**) 09-27-2010, 04:14 PM

Quote:

Originally Posted by dragongirl81

Lurker2010, I've noticed that you've been crabbing about that "paper plate analogy" for almost a year now. I have two questions for you:

1. What's wrong with it?
2. Why won't you let it go? Even if it is a "bogus analogy," nobody mentioned paper plates in this thread, but you had to bring it up again.

Knotlob, you're a pretty sharp guy, are you familiar with this "paper plate analogy"? What do you think about it?

You brought up "pet peeves" I didn't realize you intended to limit the discussion to only pet peeves posted in this thread.

All regular soft lenses are made of similar polymers. I'm excluding the newer silicone hydrogel lenses. In fact some of daily lenses are exactly the same as planned replacement lenses. The only difference is the packaging and care instructions. Think of a heavy paper plate. Half of the plates off the production line go into packaging that says use once and throw out. The other half goes into packaging that says made well enough to clean and use again. Similar analysis with plastic utensils. Some are made well enough to go into a dishwasher.

The analogy is not only bogus since all the lenses are made of similar polymers, they're all paper plates.

Starr · #34 (**permalink**) 09-27-2010, 04:48 PM

Quote:

Originally Posted by lurker2010

The point of the threads is suggesting that, at least in the past, daily disposable lenses were the same (or substantially the same) as 14 day lenses.

Okay, I'm new to this thread and it sounds like the debate has been raging for some time. You said that " . . . at least in the past, daily disposable lenses were the same (or substantially the same) as 14 day lenses." Does than mean that this is no longer true?

If it is true that some companies are selling the same lenses as both daily and extended wear, what can we do to put a stop to this deceptive practice?

For what it's worth. I've read about this "bogus paper plate analogy" on this forum, and I don't see what's wrong with it. Some plates are made of cheap paper and intended to be used just once and thrown away so you don't have to spend a lot of money on them, while others are made of stronger stuff and intended to be washed and reused. It's the same with contact lenses, right? Some contacts you clean and reuse, and others you just throw away after one use. What's the big debate about?
Do you not agree that paper plates should only be used once, or do you disagree that glass or plastic plates should be washed and used again?

Perhaps you believe that contact lenses that are called "daily disposable" lenses are neither daily nor disposable? Tell us what you think. If you've already said so someplace else, maybe you can just summarize here. Let's just come right out and say it plainly.

Knotlob · #35 (**permalink**) 09-27-2010, 04:52 PM

Quote:

Originally Posted by dragongirl81

Lurker2010, I've noticed that you've been crabbing about that "paper plate analogy" for almost a year now. I have two questions for you:

1. What's wrong with it?
2. Why won't you let it go? Even if it is a "bogus analogy," nobody mentioned paper plates in this thread, but you had to bring it up again.

Knotlob, you're a pretty sharp guy, are you familiar with this "paper plate analogy"? What do you think about it?

Lurker2010 and myself share similar views on rewearing disposable contact lenses. In some circumstances, it is entirely possible to reuse a Disposable Lens. I have tried it with a Bausch & Lomb SofLens Daily and it lasted 10 weeks, but I got bored and stopped the test (as it was only an experiment for my own interest and I don't generally wear Daily Disposable contact lenses). The Monthly and the Daily versions of that lens are made of the same material, but the monthly lens is fractionally thicker lens (0.09 versus 0.14mm for a -3.00D lens). You can find similar examples of this sort of thing or even the same lens being used for different duty life cycles, particularly on the US FDA Website if you care to look.

Caveat.

Both Lurker2010 and myself repeatedly point out that there may be very good reasons for wearing a Daily Lens only one day as prescribed by your Eye Care Practitioner. e.g. pollen allergies, travelling convenience, inability or unwillingness to look after/properly disinfect/clean the lenses for the next day's wear, physical disabilities, heavy protein deposits, etc.

I wore vial lenses for maybe 30+ years and they are worn day after day, but are not hugely different to the hydrogel monthly replacements, etc. though they would get protein deposits on them by about 9 months. I switched to silicone hydrogel monthly on the recommendation of my eye care professional, as they offer superior oxygen permeability. I don't wear disposable lenses outside their recommended life cycle, but if I chose to do so, I would go with a silicone hydrogel for the newer technology benefits. (Currently am wearing RGP lenses).

I have yet to get a proper explanation from the manufacturers why it is bad to exceed their (soft lens) recommended life cycle, though some unofficially will tell you that it is possible, provided you thoroughly disinfect the lenses and check them rigorously for protein build up, rips, etc. Many wearers these days don't want to spend the time doing this and it is better if they stick with low maintenance Daily Disposable lenses.

I don't wear Daily Disposables and when I wear soft lenses, I would be wearing a Silicone Hydrogel monthly lens.

I don't think the paper plate analogy really applies here. Or if you want to stick with this analogy, in some cases, manufacturers have been known to package their 'paper plates' as Fine Wedgwood China and charge appropriately.

I don't want any forum reader or guest coming to this post and saying "Oh Yes, I can wear any Daily Disposable lens for as long as I want and not bother about these mundane things such as cleaning and lens care" and consequently develop severe eye problems. You cannot do this with every Daily Disposable lens and it depends entirely on an individual's eye health, their attitude to lens care and what they want from the contact lenses.

knotlob

Sox05 · #36 (**permalink**) 09-27-2010, 05:18 PM

Quote:

Originally Posted by Knotlob

Lurker2010 and myself share similar views on rewearing disposable contact lenses. In some circumstances, it is entirely possible to reuse a Disposable Lens. I have tried it with a Bausch & Lomb SofLens Daily and it lasted 10 weeks, but I got bored and stopped the test (as it was only an experiment for my own interest and I don't generally wear Daily Disposable contact lenses). The Monthly and the Daily versions of that lens are made of the same material, but the monthly lens is fractionally thicker lens (0.09 versus 0.14mm for a -3.00D lens). You can find similar examples of this sort of thing or even the same lens being used for different duty life cycles, particularly on the US FDA Website if you care to look.

Caveat.

Both Lurker2010 and myself repeatedly point out that there may be very good reasons for wearing a Daily Lens only one day as prescribed by your Eye Care Practitioner. e.g. pollen allergies, travelling convenience, inability or unwillingness to look after/properly disinfect/clean the lenses for the next day's wear, physical disabilities, heavy protein deposits, etc.

I wore vial lenses for maybe 30+ years and they are worn day after day, but are not hugely different to the hydrogel monthly replacements, etc. though they would get protein deposits on them by about 9 months. I switched to silicone hydrogel monthly on the recommendation of my eye care professional, as they offer superior oxygen permeability. I don't wear disposable lenses outside their recommended life cycle, but if I chose to do so, I would go with a silicone hydrogel for the newer technology benefits. (Currently am wearing RGP lenses).

I have yet to get a proper explanation from the manufacturers why it is bad to exceed their (soft lens) recommended life cycle, though some unofficially will tell you that it is possible, provided you thoroughly disinfect the lenses and check them rigorously for protein build up, rips, etc. Many wearers these days don't want to spend the time doing this and it is better if they stick with low maintenance Daily Disposable lenses.

I don't wear Daily Disposables and when I wear soft lenses, I would be wearing a Silicone Hydrogel monthly lens.

I don't think the paper plate analogy really applies here. Or if you want to stick with this analogy, in some cases, manufacturers have been known to package their 'paper plates' as Fine Wedgwood China and charge appropriately.

I don't want any forum reader or guest coming to this post and saying "Oh Yes, I can wear any Daily Disposable lens for as long as I want and not bother about these mundane things such as cleaning and lens care" and consequently develop severe eye problems. You cannot do this with every Daily Disposable lens and it depends entirely on an individuals eye condition and their attitude to lens care and what they want from the contact lenses.

knotlob

Thanks for that explanation, Knotlob. Especially that final point. The idea that someone would come on this site and suggest that everyone should disobey package directions (and even doctor's instructions) and wear daily disposable lenses for a week or so fills me with horror. Your 10 week experiment doesn't exactly make me feel all warm and fuzzy either.

The thing is, some people are so impressionable, and so quick to cry "rip-off" that they'll risk their health to prove that they're right and the Big Evil Corporations are wrong. I really don't want that to happen. I would feel just horrible if someone damaged their eyes because they followed something that they read on Lens 101.

What about this? Suppose you do a little research and discover that daily lens A is made of 60% fictionfilcon and 40% water, but so is monthly lens B. Exactly the same. Why do people then draw the conclusion that both must be monthly lenses? Maybe they're both daily lenses.

Let me put it this way. If it's true that people are throwing away their contacts too soon, so what? They're wasting money. That's a shame, but not nearly as tragic as those who wear their contact lenses too long and injure their eyes. I'd rather err on the side of caution.

Knotlob · #37 (**permalink**) 09-27-2010, 06:10 PM

Quote:

Originally Posted by Sox05

Thanks for that explanation, Knotlob. Especially that final point. The idea that someone would come on this site and suggest that everyone should disobey package directions (and even doctor's instructions) and wear daily disposable lenses for a week or so fills me with horror. Your 10 week experiment doesn't exactly make me feel all warm and fuzzy either.

The thing is, some people are so impressionable, and so quick to cry "rip-off" that they'll risk their health to prove that they're right and the Big Evil Corporations are wrong. I really don't want that to happen. I would feel just horrible if someone damaged their eyes because they followed something that they read on Lens 101.

What about this? Suppose you do a little research and discover that daily lens A is made of 60% fictionfilcon and 40% water, but so is monthly lens B. Exactly the same. Why do people then draw the conclusion that both must be monthly lenses? Maybe they're both daily lenses.

Let me put it this way. If it's true that people are throwing away their contacts too soon, so what? They're wasting money. That's a shame, but not nearly as tragic as those who wear their contact lenses too long and injure their eyes. I'd rather err on the side of caution.

Well in the case of a lens made from fictionfilcon, some people will only be able to wear the lens on a Daily Disposable wear basis. But some would have been able to wear the fictionfilcon lens (packaged as a Daily and a Monthly Disposable lens but in different packaging).

Obviously, the manufacturer is going to charge more for the Monthly Disposable lens because it is a 'better lens' i.e. you can wear it 30 times. But in reality, those people who can wear the fictionfilcon lens as a Monthly Disposable lens are paying more than they need to, if the manufacturer were honest and said if you want Monthly Disposables, just buy our Daily Disposable fictionfilcon lens.

knotlob

lurker2010 · #38 (**permalink**) 09-27-2010, 07:34 PM

To answer Knoblot's question--Many studies suggest "no rub" cleaning doesn't do an adequate job. The FDA is considering, not sure if the change was already done, requiring manufacturers of solutions change the wording. No longer claim the product is "no-rub" (at least in the big print). Require that "rub" instructions also be included.

It's questionable if all of the currently produced daily disposable (or even 14 day lenses) will hold up (without ripping) to the kind of rub cleaning that may be required if you want to use daily disposable lenses for more then a few days.

Captainteneel · #39 (**permalink**) 09-28-2010, 10:22 AM

Quote:

Originally Posted by Knotlob

Well in the case of a lens made from fictionfilcon, some people will only be able to wear the lens on a Daily Disposable wear basis. But some would have been able to wear the fictionfilcon lens (packaged as a Daily and a Monthly Disposable lens but in different packaging).

Obviously, the manufacturer is going to charge more for the Monthly Disposable lens because it is a 'better lens' i.e. you can wear it 30 times. But in reality, those people who can wear the fictionfilcon lens as a Monthly Disposable lens are paying more than they need to, if the manufacturer were honest and said if you want Monthly Disposables, just buy our Daily Disposable fictionfilcon lens.

knotlob

Interesting thread here.

It sounds like you're saying that contact lens wear time can simply be a personal thing. My eye doctor may tell me that I can wear the 60% "fictionfilcon" lenses for a month, but the same doctor could tell you to change them every day. If that's the case, then it's just physiology, and not the Big Evil Corporation (As Sox05 put it.) trying to cheat us, right?

I just don't like people pointing fingers and making accusations. Shouldn't we use this forum to encourage contact lens wear? All this talk about no-good, lying, cheating contact lens manufacturers (In this thread and others.) doesn't really help anybody. It just makes people mad. Some people are mad because they're being cheated, and other people are mad because they think the first group of people are spreading rumors. What's the point of all that? Can someone show me the good that comes out of it?

Knotlob · #40 (**permalink**) 09-28-2010, 10:39 AM

Quote:

Originally Posted by Captainteneel

Interesting thread here.

It sounds like you're saying that contact lens wear time can simply be a personal thing. My eye doctor may tell me that I can wear the 60% "fictionfilcon" lenses for a month, but the same doctor could tell you to change them every day. If that's the case, then it's just physiology, and not the Big Evil Corporation (As Sox05 put it.) trying to cheat us, right?

I just don't like people pointing fingers and making accusations. Shouldn't we use this forum to encourage contact lens wear? All this talk about no-good, lying, cheating contact lens manufacturers (In this thread and others.) doesn't really help anybody. It just makes people mad. Some people are mad because they're being cheated, and other people are mad because they think the first group of people are spreading rumors. What's the point of all that? Can someone show me the good that comes out of it?

I would suggest this forum is about knowledge. People come here looking for information.

Now, from what I have learnt, there are some pretty dubious practices, which have been or are being practised at present and these are quite definitely NOT in the best interests of the paying customer - that's you and me.

It is not always the manufacturers who are doing these things, though they may facilitating others to deceiver the public. e.g. the practice of rebranding contact lenses (especially Cooper Vision ones) so that an opticians chain can say that we think this particular lens is the best for you and we can sell it to you my boy for just €400/year's supply, whereas with knowledge you will find the same lens with a different name is available on-line for only €200/years supply.

When I got my new lenses roughly this time last year, I was quite naive and didn't realise this deception was quite widespread. But now I understand a lot more of what is going on, so I don't take what an optician's chain may tell me as gospel, without a reality check.

knotlob

Ordersixtysix · #41 (**permalink**) 09-28-2010, 11:01 AM

Quote:

Originally Posted by Knotlob

I would suggest this forum is about knowledge. People come here looking for information.

Now, from what I have learnt, there are some pretty dubious practices, which have been or are being practised at present and these are quite definitely NOT in the best interests of the paying customer - that's you and me.

It is not always the manufacturers who are doing these things, though they may facilitating others to deceiver the public. e.g. the practice of rebranding contact lenses (especially Cooper Vision ones) so that an opticians chain can say that we think this particular lens is the best for you and we can sell it to you my boy for just €400/year's supply, whereas with knowledge you will find the same lens with a different name is available on-line for only €200/years supply.

When I got my new lenses roughly this time last year, I was quite naive and didn't realise this deception was quite widespread. But now I understand a lot more of what is going on, so I don't take what an optician's chain may tell me as gospel, without a reality check.

knotlob

Thanks for helping us shake away the cobwebs, Knotlob. I agree with Captainteneel that some of these "Big Evil Corporation" posts are getting tedious, and I also agree with you that we need to be careful of eye doctors who may not be on the up and up. It's easier for me to believe in a corrupt individual than a corrupt corporation. It's hard to keep corporate secrets.

Knotlob · #42 (**permalink**) 09-28-2010, 03:27 PM

Quote:

Originally Posted by Ordersixtysix

Thanks for helping us shake away the cobwebs, Knotlob. I agree with Captainteneel that some of these "Big Evil Corporation" posts are getting tedious, and I also agree with you that we need to be careful of eye doctors who may not be on the up and up. It's easier for me to believe in a corrupt individual than a corrupt corporation. It's hard to keep corporate secrets.

You need to believe in corrupt corporations also. Some have been exposed and made multimillion dollar out of court settlements in order to avoid class action court trials and determinations. There has been much discussion on this forum in the last week.

knotlob

scienceinproducts · #43 (**permalink**) 01-09-2011, 12:19 AM

Quote:

Originally Posted by lurker2010

Nice picture of a $20 bill. Doesn't do anything to advance the discussion. A patient who wears daily disposable lenses for 2 or 3 consecutive days (taking them out at night and properly disinfecting them) will save more then $20.

You said "people will do anything for money" Are you referring to customers who save money be using daily disposable lenses for more then a single days or are you talking about lens manufacturers who market the same, or substantially the same lens, with different replacement schedules at different prices?

Are you talking about the company that is subject to investigation by California consumer affairs and class action law suits? The company claimed their multip purpose product was "new and unique". The identical product is sold by COSTCO, under the Kirkland brand name, at a lower price. "Do anything for money" certainly applies.

What's the company/brand?

scienceinproducts · #44 (**permalink**) 01-09-2011, 12:37 AM

Quote:

Originally Posted by chemist

there is no lens degradation from enzyme cleaners

I disagree. Enzymes are proteins, which tend to get stuck into lens surfaces. That's why you can't use enzymatic cleaners indefinitely to clean the same pair of lenses.

I wrote a detailed explanation here:

http://scienceinproducts.blogspot.com/2011/01/normal-0-false-false-false-en-us-x-none.html

Purpleiris · #45 (**permalink**) 01-10-2011, 11:44 AM

Quote:

Originally Posted by scienceinproducts

I disagree. Enzymes are proteins, which tend to get stuck into lens surfaces. That's why you can't use enzymatic cleaners indefinitely to clean the same pair of lenses.

I wrote a detailed explanation here:

http://scienceinproducts.blogspot.com/2011/01/normal-0-false-false-false-en-us-x-none.html

I suppose it depend on what you mean by "degradation." In my mind, "degradation" means "breaking down." Like what happens when paper is left lying around. It fades, becomes brittle and disintegrates. I don't think that happens to contact lenses until a very long time has gone by, although in the case of daily lenses that might not be such a long time.

PTUser · #46 (**permalink**) 02-10-2011, 03:55 PM

Quote:

Originally Posted by scienceinproducts

I disagree. Enzymes are proteins, which tend to get stuck into lens surfaces. That's why you can't use enzymatic cleaners indefinitely to clean the same pair of lenses.

I wrote a detailed explanation here:

http://scienceinproducts.blogspot.com/2011/01/normal-0-false-false-false-en-us-x-none.html

Uh oh. It looks like we have a rumble between scienceinproducts and chemist. Who will win the Battle of the Brains?

ReTina · #47 (**permalink**) 02-10-2011, 05:42 PM

Quote:

Originally Posted by lurker2010

Some people think it's crazy to throw out a perfectly good lens after only one wearing.

Some companies marketed the identical lens as both daily disposable and as planned replacement lenses.

Some manufacturers still file a lens with the FDA for use as a daily lens and for planned replacement. The eye practitioner decides on the wear schedule and disinfection regime.

Some patients can safely wear a daily lens for more then one day.

Patients who wear daily disposable lenses don't need to bother with cleaning solutions and cases. Properly cleaning and disinfecting a daily use lens negates the advantage of using a daily lens.

Having to buy and use Clearcare and saline kind of defeats one of the advantages of using a daily disposable lens.

Daily disposable lenses tend to rip when subjected to the kind of rub cleaning that's necessary to maintain the lenses for more then 2 or 3 days.

Some patients, and even some eye doctors, consider the manufactures labeling more of a suggestion. I'd never get more then about 10 days out of a 14 day lens or 60 days out of a 3 month lens.

Some people can safely wear a lens for more then suggested by the mfg. Some people can't even wear them for the suggested wear schedule.

There is no substitute for examining your lens for rips, small tears and deposits that you can't remove.

Good post Lurker. Picking up your final point, it's a good idea to inspect your contacts for damage and wear, and it's also important to follow your doctor's instructions. If she says to throw your contact lenses out every night before you go to bed, then that's what you should do. If she tells you that you can wear them for two days, then you could probably get a way with it. After all, if you wear your contact lenses too long, and then go to your doctor because your eyes hurt, you're not going to get a lot of sympathy. I don't know about you, but I hate getting lectured by the doctor.

unclebuck · #48 (**permalink**) 03-08-2011, 12:21 PM

Quote:

Originally Posted by ReTina

Good post Lurker. Picking up your final point, it's a good idea to inspect your contacts for damage and wear, and it's also important to follow your doctor's instructions. If she says to throw your contact lenses out every night before you go to bed, then that's what you should do. If she tells you that you can wear them for two days, then you could probably get a way with it. After all, if you wear your contact lenses too long, and then go to your doctor because your eyes hurt, you're not going to get a lot of sympathy. I don't know about you, but I hate getting lectured by the doctor.

Yeah, I hate getting lectured by my doctor, too, especially since I do what he says most of the time.

lurker2010 · #49 (**permalink**) 03-08-2011, 12:33 PM

Quote:

Originally Posted by ReTina

Good post Lurker. Picking up your final point, it's a good idea to inspect your contacts for damage and wear, and it's also important to follow your doctor's instructions. If she says to throw your contact lenses out every night before you go to bed, then that's what you should do. If she tells you that you can wear them for two days, then you could probably get a way with it. After all, if you wear your contact lenses too long, and then go to your doctor because your eyes hurt, you're not going to get a lot of sympathy. I don't know about you, but I hate getting lectured by the doctor.

I'm not sure what you mean by "probably get a way with it". Some of the companies market the identical lens for daily use and for planned replacement. Your comment assume there may something wrong with that recommendation.

Pudgefisk · #50 (**permalink**) 03-08-2011, 12:38 PM

Quote:

Originally Posted by lurker2010

I'm not sure what you mean by "probably get a way with it". Some of the companies market the identical lens for daily use and for planned replacement.

You can prove that, right?

lurker2010 · #51 (**permalink**) 03-08-2011, 08:21 PM

Quote:

Originally Posted by Pudgefisk

You can prove that, right?

Go the FDA website. Read the filings. I won't list the brand(s) or provide a direct link. Just because the lens is capable of being re-used doesn't mean every patient should wear the lens more then once. People who want to wear lenses more then suggested by the mfg either need the recommendations of their eye doctor or do their own research. Probably both.

I suspect one of the reasons for daily disposable is to avoid the need to educate patients how to clean, disinfect and remove protein from the lenses. To avoid having to educate patients how to examine their lenses for tears and contamination.

I previously gave a link to knotlob via PM but will not be posting it, nor providing it via PM to others.

edited to add some lens manufacturers market the same lens in different countries, with different suggested replacement schedules.

Cheezhed · #52 (**permalink**) 03-09-2011, 11:27 AM

Quote:

Originally Posted by lurker2010

Go the FDA website. Read the filings. I won't list the brand(s) or provide a direct link. Just because the lens is capable of being re-used doesn't mean every patient should wear the lens more then once. People who want to wear lenses more then suggested by the mfg either need the recommendations of their eye doctor or do their own research. Probably both.

I suspect one of the reasons for daily disposable is to avoid the need to educate patients how to clean, disinfect and remove protein from the lenses. To avoid having to educate patients how to examine their lenses for tears and contamination.

I previously gave a link to knotlob via PM but will not be posting it, nor providing it via PM to others.

edited to add some lens manufacturers market the same lens in different countries, with different suggested replacement schedules.

Okay, if I go to www.fda.gov, what keywords to I use to find these filings that show that lenses with different brand names are really the same?

I totally agree with you that if anyone wants to wear contact lenses of any kind, they need to see an eye care professional and get advice from them as to what kind of lenses to get and how long to wear them. Each person is different. As for doing one's own research, I'd be careful on that one. I can "research" the fact the Elvis is alive and well and living on Venus. You have to make sure that your sources are trustworthy.

(Just as an aside, I did actually find a website that demonstrates the different gravitational pull on the planets of our Solar System by calculating the King's weight on each. If Elvis weighed 255 lbs. on Earth, he would have weighed 232 lbs. on Venus--97 on Mars. Isn't the Internet wonderful?)

lurker2010 · #53 (**permalink**) 03-09-2011, 07:26 PM

Quote:

Originally Posted by Cheezhed

As for doing one's own research, I'd be careful on that one. I can "research" the fact the Elvis is alive and well and living on Venus. You have to make sure that your sources are trustworthy.

My source is the FDA 510(k) reports. I already told you my source. Kind of rude to equate that with your research regarding Elvis.

Contact lenses are a medical device. Start with that for your keyword search. You're on your own.

edited to add People interested in research could also check and see if their lens mfg is marketing the same lens (same brand or same lens with a different brand name) in other countries but with a longer suggested interval between lens replacements.

At first I was going to say your Elvis comment was very rude. BUT you make a good point. Posters who insist that all daily lens brands are significantly different then lenses marketed for planned replacement are the people who think Elvis is alive.

LeeRoberts · #54 (**permalink**) 03-10-2011, 12:45 PM

Quote:

Originally Posted by lurker2010

My source is the FDA 510(k) reports. I already told you my source. Kind of rude to equate that with your research regarding Elvis.

Contact lenses are a medical device. Start with that for your keyword search. You're on your own.

edited to add People interested in research could also check and see if their lens mfg is marketing the same lens (same brand or same lens with a different brand name) in other countries but with a longer suggested interval between lens replacements.

At first I was going to say your Elvis comment was very rude. BUT you make a good point. Posters who insist that all daily lens brands are significantly different then lenses marketed for planned replacement are the people who think Elvis is alive.

Wow. Where'd you get your attitude? Can I get one too? I'd want to look down my nose at all those poor people that aren't as clever as me.

Eyeofharmony · #55 (**permalink**) 03-10-2011, 04:21 PM

Quote:

Originally Posted by lurker2010

My source is the FDA 510(k) reports. I already told you my source. Kind of rude to equate that with your research regarding Elvis.

I think Cheezhed was saying that when people start doing their own research without a little direction, they might come to some very odd conclusions, as you apparently have in your response. As near as I can tell, there was no attack on you, personally, lurker.

lurker2010 · #56 (**permalink**) 03-10-2011, 04:54 PM

Quote:

Originally Posted by LeeRoberts

Wow. Where'd you get your attitude? Can I get one too? I'd want to look down my nose at all those poor people that aren't as clever as me.

I mentioned research and what can be found by reading FDA filings. A poster commented:

Quote:

I'd be careful on that one. I can "research" the fact the Elvis is alive and well and living on Venus. You have to make sure that your sources are trustworthy.

You tell me who has the attitude?

Maybe the post didn't read the way it was intended. If so I accept the implied apology.

RawBob · #57 (**permalink**) 03-10-2011, 05:32 PM

Quote:

Originally Posted by lurker2010

I mentioned research and what can be found by reading FDA filings. A poster commented:

You tell me who has the attitude?

Maybe the post didn't read the way it was intended. If so I accept the implied apology.

You quoted "Chezhed" and his/her Elvis/Venus remark. I don't know what was intended, but it looked to me like they were saying that if you turn someone loose and tell them to do their own research, who knows where they'll end up?

You come on this site making accusations and when people want evidence to support your claim, you tell them "look it up." Naturally when you make a statement like that, people will challenge it. The burden of proof is yours, Lurker2010. You made the statement, now you should be the one to back it up.

Lens101 is intended for the members to help each other. You said "go to the FDA website." That doesn't really help. This is a long thread, so I might have missed it, but I didn't see anything that looked like a URL to the particular page at www.fda.gov that has the evidence that supports your claim that "some of the companies market the identical lens for daily use and for planned replacement." That's a big site. Websites that have the .gov suffix can be very large.

I'm not saying I disagree with your statement. In fact, I really want to see this proof that some daily lenses are the same as "planned replacement," but I'm really not interested enough to go sniffing around Google and fda.gov. I suspect many others who are reading this thread feel the same.

Go ahead. Prove your point, lurker 2010. Make your doubters eat their words. Don't make them go to other sites, possibly get lost, and miss your point. Answer those challenges here and now.

Thank you.

lurker2010 · #58 (**permalink**) 03-11-2011, 09:45 AM

I already posted a direct quote from the relevant FDA 510(k). I already said I won't post a direct link or the identify contact(s). I don't want to, even indirectly, encourage posters to overwear their contact. Daily disposable contacts are intended, in part, for patients who are unable or unwilling to properly clean, disinfect and examine their contacts on a daily basis.

Some people are just too lazy to care for their contacts. Some people are too lazy to do their own research. You don't need google. The FDA site lists contacts as a medical device.

Daily disposable contacts are sold for convenience. People who plan on cleaning them are defeating the purpose of dailies and might as well consider other contacts.

I'm guilty in these threads of refuting posters who falsely claim no daily disposable lens can be worn for more then one day but ignoring the reality. Most patients are unwilling or unable to do what's required to clean and disinfect their contacts.

BusDriver · #59 (**permalink**) 03-11-2011, 10:42 AM

Quote:

Originally Posted by lurker2010

I already posted a direct quote from the relevant FDA 510(k). I already said I won't post a direct link or the identify contact(s). I don't want to, even indirectly, encourage posters to overwear their contact. Daily disposable contacts are intended, in part, for patients who are unable or unwilling to properly clean, disinfect and examine their contacts on a daily basis.

I haven't got any proof, but I suspect you're right in that daily contact lenses have a built in margin of safety. Human beings being the way that they are, if you tell them to wear their contact lenses from morning until evening and no more, they're going to try and push the boundaries. I don't think the manufacturers are being deceptive, just cautious.
Like you, I don't want to encourage people to over wear their contact lenses, so I'm going to state very clearly that anyone reading this site who has been told by their eye doctor to take their contact lenses out every night--by all means, please do so.

lurker2010 · #60 (**permalink**) 03-11-2011, 03:55 PM

Quote:

Originally Posted by BusDriver

I haven't got any proof, but I suspect you're right in that daily contact lenses have a built in margin of safety. Human beings being the way that they are, if you tell them to wear their contact lenses from morning until evening and no more, they're going to try and push the boundaries. I don't think the manufacturers are being deceptive, just cautious.
Like you, I don't want to encourage people to over wear their contact lenses, so I'm going to state very clearly that anyone reading this site who has been told by their eye doctor to take their contact lenses out every night--by all means, please do so.

I'm talking about people removing a lens, marketed for daily disposable use, at night. I'm assuming the person cleans and disinfects the lens before wearing it the next morning.

I'm not talking about leaving your lens in your eye overnight. That's completely different. You don't blink when you sleep. Many daily disposable lenses won't let enough oxygen get to your cornea when you sleep. There are some studies, and some doctors, who don't think it's a good idea for most people to sleep in any contacts.

captainneo · #61 (**permalink**) 03-11-2011, 04:06 PM

Quote:

Originally Posted by lurker2010

I'm talking about people removing a lens, marketed for daily disposable use, at night. I'm assuming the person cleans and disinfects the lens before wearing it the next morning.

I'm not talking about leaving your lens in your eye overnight. That's completely different. You don't blink when you sleep. Many daily disposable lenses won't let enough oxygen get to your cornea when you sleep. There are some studies, and some doctors, who don't think it's a good idea for most people to sleep in any contacts.

I've heard that, too. Right here on Lens 101, among other places. There are those who say that no one should sleep in any kind of contact lenses, even if they're called "weekly" or "monthly".

kevin3205 · #62 (**permalink**) 04-06-2011, 10:14 PM

You write so good!

Georgiaonmymind · #63 (**permalink**) 04-07-2011, 12:27 PM

Quote:

Originally Posted by kevin3205

You write so good!

Who writes so good? I like RawBob's post up there with the people applauding.

Bondjamesbond · #64 (**permalink**) 04-18-2011, 12:43 PM

Quote:

Originally Posted by lurker2010

I'm talking about people removing a lens, marketed for daily disposable use, at night. I'm assuming the person cleans and disinfects the lens before wearing it the next morning.

I'm not talking about leaving your lens in your eye overnight. That's completely different. You don't blink when you sleep. Many daily disposable lenses won't let enough oxygen get to your cornea when you sleep. There are some studies, and some doctors, who don't think it's a good idea for most people to sleep in any contacts.

Can you give us a link to one or two of these studies that show that you should not sleep in any contact lenses? Is there an article that can be ready by someone who is not a doctor or a graduate student, just regular Joe?

Cheezhed · #65 (**permalink**) 04-27-2011, 05:35 PM

Quote:

Originally Posted by Bondjamesbond

Is there an article that can be ready by someone who is not a doctor or a graduate student, just regular Joe?

You mean "read" by a regular Joe, right?

unclebuck · #66 (**permalink**) 04-28-2011, 12:23 PM

Quote:

Originally Posted by Bondjamesbond

Can you give us a link to one or two of these studies that show that you should not sleep in any contact lenses? Is there an article that can be read by someone who is not a doctor or a graduate student, just regular Joe?

I'd like to see those studies myself, Bondjamesbond. Thanks for asking.

HelpMeRhonda · #67 (**permalink**) 11-23-2011, 04:42 PM

Quote:

Originally Posted by Bondjamesbond

Can you give us a link to one or two of these studies that show that you should not sleep in any contact lenses? Is there an article that can be ready by someone who is not a doctor or a graduate student, just regular Joe?

Good idea. This Regular Joe would like to read about those studies himself.

DejaVu · #68 (**permalink**) 11-24-2011, 09:31 AM

Happy Thanksgiving everyone. I'm just posting in this thread so I will automatically be subscribed to it. So rushed right now I can't read the whole thing but it looks like a good one to read tonight after all the work is done, & if I leave this post I think I'll be automatically subscribed.

Hope everyone has a great Holiday

luvbostonxo2's · #69 (**permalink**) 01-05-2012, 03:06 AM

Quote:

Originally Posted by scienceinproducts

I disagree. Enzymes are proteins, which tend to get stuck into lens surfaces. That's why you can't use enzymatic cleaners indefinitely to clean the same pair of lenses.

I wrote a detailed explanation here:

http://scienceinproducts.blogspot.com/2011/01/normal-0-false-false-false-en-us-x-none.html

enzymes are protein molecules with an ionic or anionic charge causing denatured protein to be un bound (through a magnetic attraction)from the lens polymer matrix.

So in short yes its a refined and purifiied protein molecule but the molecular size cannot enter the lens polymer matrix. theoritically IT CANNOt alter the biochemistry and physiology of the lens material or within the lens matrix.

I think hydrogen peroxide is a better agent in suquestering denatured protein deposits. The acid ph and the nature of the reaction of lens polymers causes the lens matrix to release protein from within the lens.

PTUser · #70 (**permalink**) 01-05-2012, 10:09 AM

Quote:

Originally Posted by luvbostonxo2's

enzymes are protein molecules with an ionic or anionic charge causing denatured protein to be un bound from the lens polymer matrix.

You sound so smart, luvbostonxo2's. Thanks for signing up with us. Thank you also for not "dumbing it down" although I suspect you still simplified your answer a little.

luvbostonxo2's · #71 (**permalink**) 01-05-2012, 02:15 PM

Quote:

Originally Posted by PTUser

You sound so smart, luvbostonxo2's. Thanks for signing up with us. Thank you also for not "dumbing it down" although I suspect you still simplified your answer a little.

thank you! Im more than happy to re-explain!

I think protein remover and clear care the strongest and most cleaning system ever if also combined with a daily cleaner.

nakedeyes · #72 (**permalink**) 01-06-2012, 12:16 PM

Quote:

Originally Posted by luvbostonxo2's

thank you! Im more than happy to re-explain!

I think protein remover and clear care the strongest and most cleaning system ever if also combined with a daily cleaner.

Yup, we have a lot of Clear Care fans in this forum.

LittleElvis · #73 (**permalink**) 01-24-2012, 11:56 AM

Quote:

Originally Posted by Cheezhed

(Just as an aside, I did actually find a website that demonstrates the different gravitational pull on the planets of our Solar System by calculating the King's weight on each. If Elvis weighed 255 lbs. on Earth, he would have weighed 232 lbs. on Venus--97 on Mars. Isn't the Internet wonderful?)

W'thank you. Thankyaverymuch. I'm goin' to Mars.

unclebuck · #74 (**permalink**) 02-02-2012, 05:34 PM

Quote:

Originally Posted by LittleElvis

W'thank you. Thankyaverymuch. I'm goin' to Mars.

According to Space Ghost, Elvis is going to Venus.

Well, at least SG did a song called "Hero In His Own Mind, Part 2" where he sings in an Elvis-like voice about going to Venus.

BusDriver · #75 (**permalink**) 02-09-2012, 03:20 PM

Quote:

Originally Posted by luvbostonxo2's

thank you! Im more than happy to re-explain!

I think protein remover and clear care the strongest and most cleaning system ever if also combined with a daily cleaner.

Do you recommend a particular brand of protein remover?

Bondjamesbond · #76 (**permalink**) 02-09-2012, 04:24 PM

Quote:

Originally Posted by unclebuck

According to Space Ghost, Elvis is going to Venus.

Well, at least SG did a song called "Hero In His Own Mind, Part 2" where he sings in an Elvis-like voice about going to Venus.

Yeah, I heard that one.

I'm goin' to Venus
I'm gonna do it in my space ship
I'm goin' to Venus
It's the place that's really hip.
I'm goin' to Venus
I got my toenails painted red, hey!
I'm goin' to Venus
Because no one there ever goes to bed
Come on sing with me now!

I think I'll pass . . .

HelpMeRhonda · #77 (**permalink**) 02-10-2012, 02:54 PM

Quote:

Originally Posted by Bondjamesbond

Yeah, I heard that one.

I'm goin' to Venus
I'm gonna do it in my space ship
I'm goin' to Venus
It's the place that's really hip.
I'm goin' to Venus
I got my toenails painted red, hey!
I'm goin' to Venus
Because no one there ever goes to bed
Come on sing with me now!

I think I'll pass . . .

Not exactly what you would call "touristy" is it? I guess you might still call it a "hot spot."
It's amazing to look at that picture and think that it's the surface of another planet.

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