Science: Health: Eye: Contact Lens
contact lens mold   (+4, -2)  [vote for, against]
make you own emergency contact lenses

These could be built into luggage handles, back-pack frames, bicycle seats, etc. A sterile self-curing plastic would be made available through American Express offices, ranger stations,etc. Just pour into the mold and five minutes later pull out a fresh pair of prescription lenses.
-- On-or-about, Oct 07 2000

Interesting. Only problem I can see is that curing plastic gives off volatile chemicals that at least this tyger wouldn't want anywhere NEAR his eyes. Might be better off as Quik&Geeky glasses or something.
-- StarChaser, Oct 07 2000


Don't contact lenses tend to be cut and polished before they can be worn? I don't think molded surfaces are smooth enough to work both optically and as something that you want to slide onto your eyeball. Or do you want to package a tiny, tiny lathe and automatic polisher along with the mold?
-- jutta, Oct 07 2000


I thought they were something like heavy plastic wrap heated and formed...never looked into it, as I don't wear them...
-- StarChaser, Oct 08 2000


If you could make lenses with such a simple process, they'd be cheap enough that you could just keep an extra pair or ten stashed in every possible place. Leave manufacturing to the factories...
-- egnor, Oct 08 2000


how would the mold change size + shape for different prescriptions?
-- dj_photon, Apr 17 2001


isn't this the reason that disposable contacts were developed?
-- mihali, Apr 17 2001


I think this would work better as a vending machine. Dial in your prescription (or maybe swipe a credit card, and your precise prescription info would be taken down as you are charged) and wait 60 seconds; bingo! One-day contacts.
-- Almafeta, Dec 08 2002


Most contact lenses in production today are Spherical, that is they only correct for a myopic (nearsighted) or hyperopic (far-sighted) prescription. They are made by literally spinning them into existance. A very carefully machined mold, shaped like a mushroom, is spun at a controlled speed. A drop of viscuous liquid polymer is dropped onto the head of the mold for a precisely controlled amount of time, until the centrifugal force of the spinning mold causes it to take it's characteristic shape. Contacts are made day and night by the thousands using this technique. They cost roughly 8/10th's of a single American cent in raw materials and labor to produce in this fashion (though the machinery and technicians that maintain the machinery are disgustingly expensive). In short, the peel-off container they usually come in cost more to produce then the contact itself. No static molding techniques have been developed yet to produce contacts economically. Polishing and lathing of Compound (astigmatism) lenses and hard contact lenses is much more grueling and time intensive, which is why people with lots of astigmatism pay so much more for a single pair of contacts, yet people with simple prescriptions can buy daily disposable lenses for $25 for a months supply. So, unless you have a way to incorporate a multi-million dollar contact lens manufacturing plant onto your bike seat... -
-- eyeguy, Jan 27 2004


eyeguy -- offtopic but as you seem incredibly knowledgeable on this topic -- opinion on laser surgery?
-- theircompetitor, Jan 27 2004


//yet people with simple prescriptions can buy daily disposable lenses for $25 for a months supply.//

I used to wear contacts, and my perscription was simple enough that I spent about a dollar per pair. I then bought enough to last about a yr. then I stashed a pair everywhere I could think of me needing a spare pair. It worked for me.
-- babyhawk, Jan 27 2004


Good: Very high success rate, few major complications, computer-control of laser equipment makes it almost a foolproof procedure, even difficult prescriptions can be corrected to 20/25 or better.

Bad: Moderate amount of glare at night in almost 80% of all cases, most people adapt to the glare, but still quite annoying at first. Procedure is not covered by most insurance. Severe night glare problems in fully 10% of cases (no matter WHAT they tell you). Can not help people with Presbyopia ( i.e., if you use reading glasses now, you will STILL use reading glasses afterwards, once again no matter WHAT you've heard on the radio).

Recommendation: If you have the cash, do it. You are very likely to be ecstatic with the results.
-- eyeguy, Jan 27 2004



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