👁️🐽👁️

~~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.

So that's why we're not supported to open our eyes under water. Our eyeballs are suffocating!
- If our eyes can absorb oxygen from tears then they can certainly do so when submerged provided the water is sufficiently oxygenated.

Also your immune system will attack your eyes if it knows they're there. Eyes are weird.

Well that's just terrifying
- Here's how fucked up it is imagine the only difference between having eyes and not having eyes is one tiny small area that if it breaks at any moment the immune system can "find" your eyes which is why eye damage needs to be treated right away. One tiny barrier keeps your eyes from being identified and if that breaks your worst nightmare.
- It'll do the same to a man's balls, too
As someone living with an eye injury, this is a deep seated fear.
New phobia unlocked
What? Why would the immune system attack the eyes?
- Our immune system is trained how to differentiate between what is supposed to be there and what isn't only on things floating around in the blood. Certain parts of the human body - like the liquids inside our eyes - are permanently isolated from the bloodstream, and so our immune system will never have encountered anything like it. That's why if it ever enters the bloodstream it can trigger an immune response.

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.

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.
- Forever?
- Oh damn, did not know that was a risk
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).

Quit using up all the oxygen.
- It's mine, I saw it first!

So like ... Swim goggles will suffocate my eyes? 😦

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

So what you're saying is, my eyes are also lungs?

More like a giant alveolus. But inside out. With a giant sphincter in the middle. That poops light.
- Boy, after getting a notification with this reply I had a hell of a time trying to figure out what I could have possibly said to spur it
Fun fact: your intestines are also lungs. Or maybe more accurately, lungs evolved from intestines. It turns out, you can oxygenate people by sticking an oxygen supply up their ass. Which is a possible treatment for people who have suffered respiratory failure.
Proof that I'm not just blowing hot air up your butt, except maybe I am: https://www.science.org/content/article/mammals-can-breathe-through-their-intestines
- Wtf is going on with this timeline? First we have chess masters using their anus's to cheat. Then sticking a finger in your butt can fix abnormal heart rythms. And now we're going to find out that numerous of our top athletes all cheat by wearing butt plugs that release oxygen into their bowles.
- Makes some sense. If it can absorb nutrients, it can probably absorb gases too.

i came, i saw, i absorbed oxygen directly from the air

Skin breathes too.

Source?
- Mostly ocean flora but there's a lot that comes from the Amazon rainforest too.
- Some biology science magazine years ago. Googling gives mixed results. At least the upper skin cells do breathe directly.
  I'll update the text.

So if you sleep for too long you go blind?

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.
- Curious, I definately forgot to take it my contacts from time to time and it isn't fun waking up in them(though being able to see probably is kinda fun until you feel the discomfort anyways). Im curious about the whole process now, I'm going to try and find out more about this, wish me luck!

They don't need oxygen when I'm sleeping?

It is the only part of the body without a blood supply. Instead, it receives nutrients via aqueous humor (the liquid between the cornea and vitreous).
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.
And because that seemed lacking still and I’m too dumb to figure it out ChatGPT’s response:
The palpebral conjunctival blood vessels and the capillaries of the eyelids supply oxygen to the tear film behind closed lids. Oxygen diffuses from these vessels into the cornea.
You have a high concentration of blood vessels on the inside of your eyelids, which are kept in contact with the cornea by tears. It doesn’t only let oxygen through, some parts of blood (like lymph and antibodies) can also travel through the tears and into your cornea.
My brother sleeps with his eyes party open. He must be eye oxygenmaxxing. Superior eyeballs.

Also little known fact, balls are actually eyeballs. Back in the earlier days of evolution you could still see with them. It's also where the term 4 eyes comes from.

its how we used to be able to tell if we wiped enough
ladies had to get a friend to help them thats why that whole women going to the bathroom together thing came from. because they dont have balls. sadly

Meanwhile I still can't breathe through my arsehole

skill issue

today I learned

Surely the oxygen and carbon dioxide also diffuse through the aqueus humor and surrounding sclera.

Wait, so what are the bliod vein things in the eyes if not supplying the eyes

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

speak for yourself

how come when I don't blink it hurts and my eyes get red?

your eyes need to be both moist and oxygenated, the former usually requires blinking
Too much oxygen to the eyes.
Have you ever tried to breathe in a moving car?
Too much air is bad for you, dingus.
With the windows down.
- ok man relax, didn't mean to offend you. just asking...