I know there was already a contact lens thread in the GQ already but I have another question that’s been niggling at the back of my mind for some time. What is the deal with disposable lenses?
BTW I’m talking about soft lenses. I wear monthly disposables but there are weekly disposables, 2 week lenses, one day lenses and lenses you can apparently sleep in (though I wouldn’t fancy that much). What I want someone to tell me is WHAT IS THE DIFFERENCE between them all? Are we just being cheated, misinformed. What are the REAL benfits of dailies v. weeklys for example.
Please someone enlighten me!
Eagerly awaiting your pearls of wisdom on the subject…
i wear 2 week disposable lenses…i wear them for about 2 or 3 months…never EVER taking them out, i’m not sure if this is a good thing but i’ve not had problems, i’ve worn contacts for about 5 years
Same here. I wear weekly disposables, and I wear them for months and never take them out. Been wearing them for about three years, no problems whatsoever. I like them because I don’t have to worry about losing one, the way I would if I had a “permanent” pair. If one is irritating me or if I drop it, I just grab another from the box.
A couple of years ago there was a story about how one of the disposable contact lens manufacturers was selling essentially the same product as both the regular weekly disposables and as the daily disposables, but charging more for the weeklies. I’m not surprised. Chemically, there’s not much difference between dispoable contact lenses. I’m not aware of any difference between dailies and weeklies. Certainly nothing that would justify a price difference. AFAIK, they don’t make the plastic tougher or put in a fungicide or anything.
All soft dispoable contact lenses are hydrogel plastics that contain a hefty amount of water and are kept immersed in saline until you wear them. There are a handful of such plastics, and everyone uses very similar ones, although the actual blend is a jealously guarded secret. They won’t even tell you the refractive index. I know – I used to build test equipment for these lenses, and getting technical info from the companies was like pulling teeth.
In any event, I do know that you shouldn’t wear these things too long – crud builds up on them, and they’re hard to clean. The whole point is that they’re relatively inexpensive and easily replaceable, so you don’t have to.
I just want to echo CalMeacham - i wouldn’t wear disposable lenses too long. Protein builds up on the lenses, which makes them less oxygen permeable. This can damage your eyes.
I speak from personal experience. I wore a pair of monthly disposables for too long - about 4 months. Obviously i took them out at night and stuff like you’re supposed too. My eyes didn’t hurt or anything like that - no bad effects whatsoever. But when i finally went to the optician i was told blood vessels in my eyes were growing into my eye or something because of the lack of oxygen. It didn’t affect my sight, but would have done if it had continued. I wasn’t allowed to wear contacts for quite a while after that while my eyes recovered a little. They told me the damage will never be completely repaired though. Today i’m a lot more careful!
The thing is your eyes can be damaged by overwearing of contact lenses without you experiencing any symptoms whatsoever, until its far too late. So if you do wear contact lenses over their stated lifetimes, make sure you get your eyes regularly checked…
Thanks for the replies guys. It’s just as I suspected. There probably isn’t much of a difference at all but changing the lenses more frequently is probably less harmful to your eyes.
I got the thing about the enlarged blood vessels too. The optician told me that I’d been wearing my lenses too long and that the blood vessels had lengthened. She said if they reached 2 millimetres in length I wouldn’t be allowed to wear lenses any more. I thought this was due to the length of time per day one wore them though but maybe I was wrong. I wear my lenses for about a month and a half instead of a month because that’s how long the bottle of solution lasts and I always forget when I first put them in. Maybe I should be more careful…
I wear the two week disposible lenses.The thing is I ran out about a year ago, and haven’t had the money to get new ones.So what do I do? I take the last pair I have out every night, and I enzyme them every so often. I have not had one problem with them. I’ve never noticed a difference between any of the soft contacts I’ve ever worn.
The real benefit to disposables is that you don’t have to clean them the way you do with permanent ones, because you throw them out before they have a chance to get too much build up. My Optomatrist told me I can stretch them out a little if I want (I have one-month disposables), but then I have to clean them better. I would guess that if you treat disposables exactly like permanent ones - daily cleaning, weekly enzyme treatments, etc. you could wear them much longer.
Since most people do not clean their contacts as well as they should, disposables are a safer way to go. Unfortunately, when people find out that disposables are very similar or the same as the permanent ones, they do not treat them the same but still wear them longer. You can do damage to your eyes this way, as others have pointed out.
I also developed a reaction to the protein build-up when I wore permanent contacts even thought I cleaned them regularly. You can’t prevent some build-up over time. Now I clean my disposables regularly (even though I don’t have to) because my eyes are extra sensitive to the build up.
The best thing to do is stick to your schedule - if you want to extend the life of them ask your Dr. how to clean them. I’ve had several eye infections and it’s not worth the risk to get a few more weeks out of them. You really should take them out at night, too (unless you have the kind specifically designed for that). You do get build-up and after a while your eyes don’t get the oxygen they need.
Yikes! :eek: You’ve been wearing the same pair of disposable lenses for an entire year? I doubt that a periodic cleaning could totally clean all protein deposits and the lenses have probably changed chemically at this point. You’re very lucky that nothing bad has happened yet (like the fun that is GPC-Giant Papillary Conjunctivitis).
Why should it matter if they are disposible.I remember when they first came out with soft lenses they were good for a year.I clean my lenses just as if they were non-disposible contacts.I see no difference.
I’ve been doing various contact lens trials, there is quite a significant difference between them, even if you can’t see it with the naked eye.
My last trial was for those monthly contact lenses that you sleep in. These are a lot thicker than monthly disposables. While looking in <i>Biomaterials </i> journal, I saw a paper on SEM (scanning electron microscopy) on three different types of these lens and they all looked very different. I can find the paper for you, but you probably can’t read it if you don’t have the subscription.
I always found that after a month of normal monthly disposables (not the ones you sleep in) they were so manky they fell out by themselves. I also found that doing martial arts, the extra thickness of monthly disposibles made them more likely to get knocked out. Daily disposibles it is these days.
FYI, the most recent study that’s on at the moment (the studies full, so I can’t go onit ) is on wearing big thick contacts at night, which reshape your cornea, hopefully permenantly. Beats laser surgery any day!
I’d be really interested in seeing that study Daftbugger.
However it all seems so woolly. Why don’t opticians give people proper information on the differences between these lenses? Is it because they think we’re too stupid to care/understand?
There must be some element of trying to pull the wool over our eyes - especially given the price difference between the various types of lenses.
If disposables can be used in the same way as non-disposables provided you clean them in the same way as you would non-disposables then why are there different types of disposables?
I want facts. What IS the difference?
If there are any opticians out there come on - put your money where your mouth is and clear this up!
I asked my optometrist this question a couple of years ago. He said that if you are cleaning your lenses properly, the cleaning supplies cost more than buying disposable contacts. I ran the numbers at the time and found he was right. YMMV
I’m sure you’re right,but for someone on my tight budget speading a few bucks here and there doesn’t seem to hurt my pocketbook as much. I have an family of five and everyone wears glasses. The kids get theirs replaced every year sometimes more due to breakage. Seems I’m always speading money on everyone else. I have none left for me.(I’m counting the days until I graduate from college and can get a job)
The following applies only to disposable lenses: I’ve been told that lenses you sleep in are cleaner than lenses put in storage overnight because normal eyes do a better job of preventing build-up and grody growths than any solution. All my eye doctors have told me NEVER to put a lens back in my eye after that lens has fallen or been taken out. (But I do it all the time! heh heh.) The option to put lenses in storage overnight is for people who have dry eyes.
The lenses sold as extended-wear disposables come in a variety of thicknesses and gas-permeableness and the … I guess it’s a beveled edge, looks different from brand to brand. I go for thicker lenses, but that’s a personal preference.
It’s not clear to me if being infection prone in, say the feet and arms, should also indicate that you can easily get eye infections.* In any case, although about half of my major scrapes and contact dermatitis cases have developed a little bit of infect, in my lifetime of wearing and sleeping in and swimming in and crawling around in the muck in the longest-wearing lenses available on the market, I’ve never had any lens-related eye problems.
*If I’m correctly remembering speeches made at me, poor circulation is a factor in diabetic-type infection rates. The head-bone has great circulation, doesn’t it? So that might explain this.
) is on wearing big thick contacts at night, which reshape your cornea, hopefully permenantly. Beats laser surgery any day!