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Medical Eye Damage from Gelatine?

  1. Nov 5, 2007 #1

    Danger

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    Any opthalmologists or other occular medical experts out there?
    For decades, I've been making my own (usually elaborate) Hallowe'en outfits, including latex appliances. My avatar is one example of that. One thing that I've never been able to justify buying is costume contact lenses such as cat's eyes, red demon eyes and the like.
    Rather than latex in some cases, I've made small prostheses from pure gelatine mixed with about 6-10 times less water than is used for dessert Jell-o (depending upon desired consistency). It's very similar to latex or even harder rubber when set.
    It suddenly occurred to me that I could make my own contacts from that, using distilled water. That is no problem whatsoever to do, but I have no idea of whether or not it would be safe to wear them. Discomfort is not an issue, but possible damage certainly is.
    Do any of you (EXPERTS ONLY, PLEASE) have some thoughts about this?
    Thanks in advance.
     
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  3. Nov 6, 2007 #2

    Moonbear

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    I dunno Danger, I'm not too keen on sticking things in ones eye. Those costume contact lenses can be dangerous too, by the way.

    Not being any sort of expert on sticking gelatin in your eyes, the two things I'd most be concerned about with your idea are 1) introducing infection from non-sterile gelatin, and 2) physical abrasion from lumps, bubbles, imperfections, etc. Also, I would presume you'd be adding other things to the mix to color them? I'd be even more worried about whatever you were using for coloring causing problems. Also don't know if it could start to stick and be difficult getting back out from the moisture in your eyes, or how well they breathe or would allow your eyes to stay moist.
     
  4. Nov 7, 2007 #3

    Danger

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    Hi, Moonie. Thanks for the response.
    The points that you raised are pretty much the same ones that I'm worried about. Now that we have a discussion going, I can elaborate a bit upon the idea.
    Since the stuff is a liquid when moulded, I'm hoping that any surface imperfections would be on the outward facing part. The upper surface should be self-levelling. I'd have to rig up some kind of a turntable to spin the mould in order to get the top concave.
    I'm not sure how soluble it would be, but I can run some tests to find out. The consistency would be about half-way between dessert Jell-o and a Gummy Bear.
    Sterility would be difficult to achieve, but I was planning to use distilled water and nuke the powder before use (if it won't mess up the chemical structure). The colouring would be painted on the outer surface rather than being incorporated into the mix. A very thin clear-coat could be applied over the paint, and the centre would be punched out over the pupil area for vision.
    I never even thought about the gas permiability, but wasn't too concerned because old contacts were made out of glass and hard plastic and didn't 'breathe' at all.

    Hmmm... okay, you talked me out of it. Maybe I can buy contact lens 'blanks' (no perscription) from an occulist and just add the colour myself. It would certainly be easier.

    By the bye, sorry about posting this in the wrong section originally. I didn't even notice this one. :redface:
     
  5. Nov 7, 2007 #4

    Evo

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    Won't body heat start to melt the gelatin? Placing the gelatin on a moist eyeball, I don't think it would take long for it to start getting gooey and sliding.
     
  6. Nov 7, 2007 #5

    Danger

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    I've never encountered that problem with other prosthetics made from the same stuff, and it can get pretty warm after they've been glued on for a while. Remember that it has quite a low liquid content. Although it's actually a colloidal solution, it behaves similarly to a thermosetting plastic. The powder has to be dissolved in boiling water initially, but it's pretty stable once 'cured'. I can't give you any specifics, though, because I've never tried to melt it.
     
  7. Nov 7, 2007 #6

    turbo

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    No matter what type of color you want to add, you can rest assured that the stuff you've got kicking around the house/shop has not been tested for use in your eyes. If you want freaky contacts, any optical shop can order them for you - they can get cat's eye contacts, blacked out ones, whited out ones, stripes, etc, etc. And they are made by contact lens makers who have done everything possible to avoid liability issues. Jury awards tend to be massive when someone loses their eyesight, so rest assured that these novelty contact lenses are just as safe as conventional ones.
     
  8. Nov 7, 2007 #7

    jim mcnamara

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    Soft gelatin capsules (probably what you are shooting for consistency-wise) are hygroscopic.

    That means they will absorb moisture from your eyes. You will end up with a thin film of colorized sticky goo between your conjunctiva and the appliance. You do recall that moistened gummy bears are very sticky. Sounds like fun when you try to excavate the applicance from your eye, while it's still partially glued to the conjunctiva... You have medical insurance, right?

    Most good glues developed by humans early on are proteins. rabbit skin glue, gelatin glue (aka hide glue), fish glue, mucilage (plant proteins & carbos):

    http://www.frets.com/FRETSPages/Luthier/TipsTricks/KitchenGlue/kitchenglue.html
     
  9. Nov 7, 2007 #8

    jim mcnamara

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    Oh, forgot - if you try this and you can still see well enough to type let us know how it went.
     
  10. Nov 7, 2007 #9

    Danger

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    Thanks for all of the responses. Rest assured that I'm not going to attempt it now that I've seen your comments. It was just a passing idea, which is why I solicited expert advice.
    Turbo, I'm aware of the commercially available lenses; I just can't afford the damned things. :cry:
     
  11. Nov 7, 2007 #10

    turbo

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    I worked for a number of years as an optician in a very large ophthalmic practice, and we got referrals of all the people who visited optometrists and presented with medical problems that the optometrists were not qualified to treat. The number of injuries and infections relating to the mis-use of otherwise safe contact lenses was shocking, so sticking anything but a tested approved appliance in contact with your eye is definitely risky business.
     
  12. Nov 7, 2007 #11

    JasonRox

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    Man, I got colored contacts once and it's really cool. Looking in the mirror is just weird.

    I'm sure you can get some cheap ones though. Like getting one or two pairs. Most will write prescriptions for colored contacts too even if you have perfect eyesight.
     
  13. Nov 8, 2007 #12

    Danger

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    Simple coloured ones aren't too bad, but the ones with patterns such as 'Neelix' eyes (from ST Voyager) and cat types run $75 per pair here. There might be cheaper ones available on the net, but I won't buy them that way for the very reasons that Turbo pointed out. I couldn't be sure of what I'd be getting.
     
  14. Nov 9, 2007 #13
    Lon Chaney Sr. The Man of a Thousand Faces from the Silent Film Era, created a character that was blind in one eye by fashioning a sort of soft contact lens from the white skin you find in an egg.
     
  15. Nov 10, 2007 #14

    Danger

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    Hmmm... if I ever need a pure white one (quite possible), I'll keep that in mind. I think that I've even seen the movie in which he used it. Chaney was a bloody genius, and his kid wasn't too shoddy either.
     
  16. Nov 12, 2007 #15
    Even there is no refractive power in the cosmetic lenses, you do need to make sure they fit your cornea and move properly when you blink. ( One size does not fit all.) That means someone needs look at them under a slitlamp microscope while the lens is on your cornea. If the lens is too tight it can cause serious problems.

    A few years ago when these lenses were new to the public market, many were sold illegally without a prescription. Our clinic had a patient with bilateral corneal ulcers from wearing them.

    I am glad you changed your mind already:smile:
     
    Last edited: Nov 12, 2007
  17. Nov 13, 2007 #16

    Danger

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    Sounds painful, Larkspur.
    I didn't, in fact, change my mind; I just made it up based upon the responses. It was never my intention to try it unless everyone thought that it would be safe. Again, thanks all.
     
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