• Alcoholicorn@mander.xyz
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      6 hours ago

      No, the capillaries on your eyelids supply o2.

      If you fall asleep with contacts on or wear them too long, blocking the supply of O2, you will grow capillaries infront of your cornea. This is bad for vision.

  • altphoto@lemmy.today
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    11 hours ago

    Lasic surgery first cuts the cornea leaving a little flap. The doc peals the eyeball then they shoot a laser beam in various places in a pattern to ablate the lens.

    Then they put the flap back over like nothing happened, but that flat will never heal. That is why I will not be getting lasic thank you.

      • altphoto@lemmy.today
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        7 hours ago

        Lol, they all say that, but when you read the fine print…“yes, the cornea does heal after LASIK. While the corneal flap may not fully “heal” in the sense of becoming completely indistinguishable from the surrounding tissue, it does reattach and become very stable.”

        It’s like getting penis enlargement surgery buy then you get a warning afterwards… It will fully heal, but just don’t yank it too hard or hang from it for prolonged periods greater than half a second with a force equal or greater than 10 pounds. Levitra will also enlarge your left ear, which you should have trimmed to size every month by your local veterinarian… WTF! No, my eyes are not little meat DSLR cameras to go mess around with. So I don’t share the enthusiasm others do. I may indeed need a surgery in the future, but I’ll postpone it.

    • Kimjongtooill@sh.itjust.works
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      10 hours ago

      SMILE uses laproscopy, so the slit is only 3mm instead of 20mm for LASIK. Supposedly like a 3 day recovery time or maybe 2.

      Also, does it really never heal?

      • altphoto@lemmy.today
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        7 hours ago

        Hmm I gotta look into that. Yup never heals.

        There’s a new thing where they have been able to reshape the lens by first acidifying it, then returning it to normal after massaging it into a new shape… Rabbit eyes so far, not human… Because rabbits can’t scream like…like…like they were reshaping their eyeballs with acid.

        • oddlyqueer@lemmy.ml
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          7 hours ago

          Unfun fact: Rabbits actually can scream, I have had the misfortune of hearing it. It’s not a sound you forget.

        • cartoon meme dog@lemmy.zip
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          5 hours ago

          when you say lens, do you mean cornea? i thought most myopia, hyperopia, and astigmatism was caused by problems with the shape of the cornea.

          ok, i looked up this treatment, and it says “animal tissue tests”, not “animal tests”, so i suspect the rabbits are long past the point of being bothered :|

    • T156@lemmy.world
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      8 hours ago

      They supply the rest of the eye. It’s just the transparent bit on front that doesn’t get much of anything.

  • scratsearcher 🔍🔮📊🎲@sopuli.xyz
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    20 hours ago

    read it up on cornea wikipedia, seems to be true :o

    Instead, oxygen dissolves in tears and then diffuses throughout the cornea to keep it healthy.[5] Similarly, nutrients are transported via diffusion from the tear fluid through the outside surface and the aqueous humour through the inside surface.

  • nialv7@lemmy.world
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    1 day ago

    no no no, they also gets oxygen supply from the back of your eyelids (and also oxygen dissolved in you tears). otherwise you’d have to keep your eyes open when you sleep.

    edit: to correct inaccurate statements.

    • cute_noker@feddit.dk
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      7 hours ago

      So that’s why we’re not supported to open our eyes under water. Our eyeballs are suffocating!

    • hovercat@lemmy.blahaj.zone
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      23 hours ago

      Eventually, yeah. I had an issue with contacts when I was younger as I have to wear thick toric lenses, which allow very little oxygen through. I would wear them way too long, and I was warned that continuing to do so could cause eventually cause blindness

  • chaospatterns@lemmy.world
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    1 day ago

    That’s also why certain contact lenses can’t be worn overnight or for long periods of time because they aren’t as breathable. At least that’s what my eye doctor said when I got them.

    • LikeableLime@piefed.social
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      1 day ago

      Yep and if you wear them for too long your body will grow new blood vessels to supply your oxygen-starved eyes with what they need. These new blood vessels can cover your retina and can lead to blindness.

      Learned that one by sleeping in daily disposable contacts for a while and losing a significant portion of my peripheral vision.

    • RejZoR@lemmy.ml
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      1 day ago

      That’s correct. It’s generally recommended for lenses to have at least over 100 Dk/t for sleep and they need to be approved for that. Dk/t is the measured oxygen transmission through the lens material, the higher, the better. I would not recommend lenses with Dk/t of 30 and under even for daily wear as they starve eyes of oxygen. Especially since there are very affordable ones with very high Dk/t like Miru and Biofinity (around 160 iirc).