The white of your eye (the conjunctiva) is the “skin” that acts as a barrier between the orbit and the outside world. There is no communication past the conjunctiva with the back of the eye unless you make a hole in it. If you did pinch up a bit of conjunctiva near the edge of your eye with some forceps and made a small hole in it, you would be able to see behind it to the eyeball itself (the sclera). We actually do this quite routinely to get local anaesthetic round the back of the eye to numb it for surgery.
The sclera is white, but the sclera is covered by conjunctiva, which is also white, although it is thinnest and mostly transparent at the part where the it meets the cornea (the coloured part) so the white colour of that bit of your eye mostly comes from the sclera beneath it.
Edit - yes the cornea is completely transparent, but looks coloured because it lies over the iris. Apologies for oversimplifying.
> the cornea (the coloured part)
More precisely, the cornea is the transparent part *over* the coloured part that bulges outward a bit. The coloured part is the iris.
Correcting you when you say the cornea is the colored part of the eye and the conjunctiva is the white of the eye isn't being a pendant.
It's correcting very basic facts, and frankly it's calling into question your claimed expertise in this area if you're mixing those things up.
It sounds like you are saying the conjunctiva is physically attached to the eye and in order to get behind it you have to do something to cut a hole in it. Does that mean when someone’s eye pops out it ripped the conjunctiva around the entire eye? I know trauma can cause an eye to pop out and thus ripping a thin membrane at the same time would make sense. But what about seemingly spontaneous events like the actor Raul Julia had it happen when he was rubbing his eye. Or are those cases ones where what actually happened is not what was reported? Were they simply the eye popping forward but still remains “in” the socket in the sense it isn’t out and dangling like can happen from trauma.
The superior and inferior fornices of the conjunctiva are also where contact lenses end up if they move too high or low. They can't get "lost" behind the eyeball or further back in the orbit. Getting them out usually just takes patience. Occasionally you might need a opthalmologist or other doctor with the right tools and a will to poke up there and grab them for you.
This sounds like an opportunity to dispel the myth that your eyeball is somehow loose in your eye socket and can be popped out to hang down onto your cheek or something. It's quite firmly held in place with membranes and muscles, and you don't have a couple of inches of spare optic nerve behind it that can just swing on. Those people you see who can protrude their eyes indicate about as far it will go. If your eyeball comes out any more than that, lots of stuff has been torn and you'll never see out of that eye again.
> If your eyeball comes out any more than that, lots of stuff has been torn and you'll never see out of that eye again.
This isn’t even slightly true. Broken orbital bones can and do result in eyes popping out, as long as the ocular nerve is fine vision will be too as a rule.
Once the eye is put back in & the person heals? Nope. Full recovery is actually pretty common. The body is actually remarkably good at repairing damage to your muscles.
While the eye is popped out? Sure, it just sits there.
If muscles are completely severed they will be reattached surgically (though this can be tricky, because finding the "lost" part of the muscle can be very challenging), though it's rare that all of the muscles will be completely severed without the optical nerve also being severed. I doubt anything approaching full recovery would happen in that instance.
Blowout orbital fractures that result in traumatic globe luxation tend to also allow at least some of the supporting muscles to move with the eye as well, and they can stretch farther than you would think before completely severing. Certainly enough for the globe to push out past the eyelids where there's damage to the orbital socket.
If the muscles aren't severed but have tears and are stretched/weakened, they will often recover just fine given proper care and rehab.
I'm an optician, not an OD or ophthalmologist, but the number of videos I've seen of people popping their eyeballs out while removing scleral lenses is high enough that I'm going to disagree with you on that one.
Granted this is in vet med but one of my most memorable patients was an Aussie that came in with his eyeball hanging out like you see in a horror movie. Little dude was just so happy to be there and getting attention lol.
Yep, when he left our clinic our vet was confident his sight would be unharmed. It was one of the first cases I saw after starting there as a vet assistant and my job had been to keep applying lube to the eye so it wouldn't dry out before we got him into surgery. It was surreal to see and even weirder to be able to handle it to apply the lubricant.
Would you mind sharing one? I can’t find anything on the grim subreddits like r/medizzy that supports this idea. I’m prepared to be proved wrong, but the dangling-on-the-nerve image doesn’t seem to appear in reality.
There's a couple images [here](https://pdf.sciencedirectassets.com/272456/1-s2.0-S0735675700X00241/1-s2.0-073567579390062G/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEMb%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCIEqtIj97x3hi0ciLe0rQ7f2GZFMcRoaA4qvXqCaDpLTwAiEAudTQF%2BwSWK7Hky51XVmbs5poJVKs%2FljNYbYhaS701ycqsgUIHxAFGgwwNTkwMDM1NDY4NjUiDA5P587VKJaAcpvJRyqPBWyUXQknm0MGyEa1KqXRGH0CIbycWFDruhNroKhJZ9GX43Cq288B%2BPyuV8Z10J6guDvD7%2Fu6Wzzjm%2Fz3IgT%2Bsh7YKF4VdVLXLj7BZJHmG4UyiIBGsptfnAeH6wWmuyTEwPHowUy8HrDX4pyJm9HpZGh3mzNYqjw%2BCmdIA4VEOB%2FH3%2FNlHslEhyJLyWZBTcs8uiHFqFwPHjv5KzTEkd2YDYloGQOG67UF9byirLAmllRycmfJ2ijuX4fLLoAcwC5VfRrktNuBZi%2Fskk2R6R57uNhlIbj7sA7kgSu%2F9v1rIEKCHK1PHKkzcHbmnSFCCmD41gnFKa1srQ9XGAwlNPdkPLTIDftxrDkblNdaACK0TKL1HR%2FvIgvyhu%2F29dwaBYDSlWw7RbeuIFnev5FZRL%2F5qgxFsXtgYxgKNbxVR%2FzFdY%2FwTV9fRC7QUkeaylb6sE0RmUdMAijcpLIWB1AdHNEy%2FLMBCzjdidfGt%2FwyyKwc336mozoTsADWkMdmaQYricLamj0g9rrHhAoKqEjacTRFSSXZxlNtM3t5nouj%2BBCL7N4xUa9zixuspNQw1ihwsEAELLqFKXB%2F%2FP467Cd8Zn2XzDSOfJi8MDLnRRYTWamBHrg4rvqKBLTJe90OrvvmlUqxisdK%2B2F03IU4%2FsZTqapBx4J%2B6YBFcKrEy7e0SHDcsMPKI7KBGf0OYMdVTnK%2B7pC6dVgzJ%2FyO9ba4CP7QfC5z%2BcWZQ%2BFpPYpsmEakddyCIVzZzsc%2B9LVXqa%2F8L%2BVsOjqYBKdd7vPaGR1ItI1wGnoIBhx7jKpuy0hM%2Bcrz20QvSIT9Jai6lER7pwdYVW7dNEuLpPMsrPlJ5juCyi1xaES3jMauV3Rc80baGLxtpfAAHDgwha%2FAsQY6sQEUm9TDzvvJPXw3v0zsSIWM2oIbkPRg1ChgaF0GmpRSicqf3owkgZBdfcpvndM7JJnd7bUNf3O96t0fyqnjG%2FLKecXrc4Y2V0LZzH1nE3PZBx%2BOBkPYTF7u%2F8aASX9HGhHX8wjBnkCgv6XU%2FX5vmvIypErK6vfUDreN6fBPmJzwwBEDYn8gaaERFqTFIaO1r%2BQWudRjIzJ25SKDPNFq4DGLsTGHyaM%2FI5S%2FZkSYpD9FXj8%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20240429T223940Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTY4KPECYSW%2F20240429%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=3ba06431253c1f85a8a15f135345221ee38d3ea298530d1694da19d9a0ee41bf&hash=674cb6fe13ab5c397e45d54b5bf5eb0fe70014b5e51b53aea875cf1860abc8ea&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=073567579390062G&tid=spdf-f843bee2-e76b-4b14-857c-6fd639d24678&sid=b5ab9c59630f274fbf080832ce2175985fe4gxrqa&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=13175852055002075259&rr=87c2ca189f9559a4&cc=us). I can't find the exact video I'm thinking of, but I *vividly* remember a guy talking at SECO's online continuing education thing a few years ago about a dude who could basically pop his eyeball out at will, and how the way to replace it involves a paper clip (to which my answer is no, the way to replace it involves calling somebody who went to school for a hell of a lot longer than I did, and *they* can decide to reach for the paper clip.)
I know a guy who was mugged and had this happen when he was young. They basically bashed in his head with a bat, robbed him, and left him for dead. He woke up in pain and horror. He put his hanging eye in his mouth to protect it and walked to get help.
They caught and prosecuted the criminals. Little good that did him. He had to have quite a few surgeries and a plate. Permanent muscle damage to the eye doesn't allow it to line up correctly with the other one (wall-eyed). It's a permanent disability.
Horrible story.
Can some biology brain weigh in on why the eye would have at least 10cm of spare optic nerve length bundled up in there? Seems ridiculous, especially considering how valuable visual information is to survival.
Could someone explain why a *stretched* optic nerve could retain (or regain) function, while a *compressed* nerve (as in untreated glaucoma) results in permanent vision loss?
Edit: Should I repost this as a separate thread if it's too off-topic from OP's original question?
I dunno, I saw this documentary series about animals, and in one, a human hunter going after a rabbit was standing under a ledge and the rabbit pushed a boulder. The hunter looked up and his eyes shot out like 5 feet then shot back into his head before the rock eventually landed on him
I'm a bit confused by what you're saying. The conjunctiva is a transparent layer on the surface, you can see the sclera below it without any manipulation. Isn't it the orbital septum that protects the orbit from the outside?
It’s not fully transparent, you can’t see the sclera as it dives away to make the back of the eye because the conjunctiva is thick there and below it (from a few mm away from the cornea) is tenons capsule, which is another layer of tissue that lies between conjunctiva and sclera.
The conjunctiva is the structure that attaches your eyelids to your eyeball and forms the main barrier that stops foreign objects entering the orbit.
> The white of your eye (the conjunctiva)
The white is the sclera and it is covered by the conjunctiva which reflects on the inner aspect of the eyelid.
https://www.informedhealth.org/grafiken/bindehaut-schematisch_final_enjpg_replacement_image.jpg
The front part of the eye is sealed off from the back part by a membrane called the conjunctiva. The conjunctiva runs from the back edges of the eyelids into the top and bottom recesses (inferior and superior conjunctival fornices) and then cover the sclera (white part) to the edge of the cornea (clear part).
I've noticed that some pictures skip the conjunctiva for some reason. Here's a quick video describing the conjunctiva: https://www.youtube.com/watch?app=desktop&v=9hCMwptq_cg
A lot of confusion in the comments. The conjunctiva is the clear (ish) membrane that covers the white part of the eye. The conjunctiva "folds" and then connects to the inside of the eyelids, thus forming a "seal". The recessed pocket that the conjunctiva forms is called a fornix and is what keeps water from going behind the eye.
Sauce: https://i.pinimg.com/originals/07/5a/3b/075a3b290f47a38dc2f6a209b935c6d6.jpg
Is the bulbar conjunctiva separate from the fornix? How do you accommodate for movement of eyes? I don't understand the concept of a 'seal' in regards to eyes movements...
You didn't get a good answer yet so here it is: there is is a transparent membrane that is attached to the inside of your top and bottom eyelids. This membrane, called the conjunctiva, covers the front of your eyeballs totally. It looks like your eyeballs are right out there in front but there is the conjuctiva at the top and bottom of your eye sockets making sure nothing gets inside the socket.
The white of your eye (the conjunctiva) is the “skin” that acts as a barrier between the orbit and the outside world. There is no communication past the conjunctiva with the back of the eye unless you make a hole in it. If you did pinch up a bit of conjunctiva near the edge of your eye with some forceps and made a small hole in it, you would be able to see behind it to the eyeball itself (the sclera). We actually do this quite routinely to get local anaesthetic round the back of the eye to numb it for surgery.
That's horrifying, but thanks
I thought the white or the eye was the sclera, I only know this because I had scleritis. Which in turn got infected and ended up losing my eye.
The sclera is white, but the sclera is covered by conjunctiva, which is also white, although it is thinnest and mostly transparent at the part where the it meets the cornea (the coloured part) so the white colour of that bit of your eye mostly comes from the sclera beneath it. Edit - yes the cornea is completely transparent, but looks coloured because it lies over the iris. Apologies for oversimplifying.
> the cornea (the coloured part) More precisely, the cornea is the transparent part *over* the coloured part that bulges outward a bit. The coloured part is the iris.
>where the it meets the cornea (the coloured part) The iris is the colored part, the cornea is the bit that rests over the iris and under the sclera
Yes I know that. But if you want to be a pedant then you should know that the cornea is definitely not under the sclera.
Correcting you when you say the cornea is the colored part of the eye and the conjunctiva is the white of the eye isn't being a pendant. It's correcting very basic facts, and frankly it's calling into question your claimed expertise in this area if you're mixing those things up.
> conjunctiva, which is also white The conjunctiva takes on the shade of whatever it is covering: it is transparent.
Did ya check between the couch cushions?
It sounds like you are saying the conjunctiva is physically attached to the eye and in order to get behind it you have to do something to cut a hole in it. Does that mean when someone’s eye pops out it ripped the conjunctiva around the entire eye? I know trauma can cause an eye to pop out and thus ripping a thin membrane at the same time would make sense. But what about seemingly spontaneous events like the actor Raul Julia had it happen when he was rubbing his eye. Or are those cases ones where what actually happened is not what was reported? Were they simply the eye popping forward but still remains “in” the socket in the sense it isn’t out and dangling like can happen from trauma.
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The superior and inferior fornices of the conjunctiva are also where contact lenses end up if they move too high or low. They can't get "lost" behind the eyeball or further back in the orbit. Getting them out usually just takes patience. Occasionally you might need a opthalmologist or other doctor with the right tools and a will to poke up there and grab them for you.
This sounds like an opportunity to dispel the myth that your eyeball is somehow loose in your eye socket and can be popped out to hang down onto your cheek or something. It's quite firmly held in place with membranes and muscles, and you don't have a couple of inches of spare optic nerve behind it that can just swing on. Those people you see who can protrude their eyes indicate about as far it will go. If your eyeball comes out any more than that, lots of stuff has been torn and you'll never see out of that eye again.
> If your eyeball comes out any more than that, lots of stuff has been torn and you'll never see out of that eye again. This isn’t even slightly true. Broken orbital bones can and do result in eyes popping out, as long as the ocular nerve is fine vision will be too as a rule.
I’d assume all the muscles and movement would be gone though?
Once the eye is put back in & the person heals? Nope. Full recovery is actually pretty common. The body is actually remarkably good at repairing damage to your muscles. While the eye is popped out? Sure, it just sits there.
The four severed sets of muscles get back in position and reattach?
If muscles are completely severed they will be reattached surgically (though this can be tricky, because finding the "lost" part of the muscle can be very challenging), though it's rare that all of the muscles will be completely severed without the optical nerve also being severed. I doubt anything approaching full recovery would happen in that instance. Blowout orbital fractures that result in traumatic globe luxation tend to also allow at least some of the supporting muscles to move with the eye as well, and they can stretch farther than you would think before completely severing. Certainly enough for the globe to push out past the eyelids where there's damage to the orbital socket. If the muscles aren't severed but have tears and are stretched/weakened, they will often recover just fine given proper care and rehab.
I'm an optician, not an OD or ophthalmologist, but the number of videos I've seen of people popping their eyeballs out while removing scleral lenses is high enough that I'm going to disagree with you on that one.
Granted this is in vet med but one of my most memorable patients was an Aussie that came in with his eyeball hanging out like you see in a horror movie. Little dude was just so happy to be there and getting attention lol.
Could he see again after I’m assuming you popped it back in?
Yep, when he left our clinic our vet was confident his sight would be unharmed. It was one of the first cases I saw after starting there as a vet assistant and my job had been to keep applying lube to the eye so it wouldn't dry out before we got him into surgery. It was surreal to see and even weirder to be able to handle it to apply the lubricant.
Would you mind sharing one? I can’t find anything on the grim subreddits like r/medizzy that supports this idea. I’m prepared to be proved wrong, but the dangling-on-the-nerve image doesn’t seem to appear in reality.
There's a couple images [here](https://pdf.sciencedirectassets.com/272456/1-s2.0-S0735675700X00241/1-s2.0-073567579390062G/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEMb%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCIEqtIj97x3hi0ciLe0rQ7f2GZFMcRoaA4qvXqCaDpLTwAiEAudTQF%2BwSWK7Hky51XVmbs5poJVKs%2FljNYbYhaS701ycqsgUIHxAFGgwwNTkwMDM1NDY4NjUiDA5P587VKJaAcpvJRyqPBWyUXQknm0MGyEa1KqXRGH0CIbycWFDruhNroKhJZ9GX43Cq288B%2BPyuV8Z10J6guDvD7%2Fu6Wzzjm%2Fz3IgT%2Bsh7YKF4VdVLXLj7BZJHmG4UyiIBGsptfnAeH6wWmuyTEwPHowUy8HrDX4pyJm9HpZGh3mzNYqjw%2BCmdIA4VEOB%2FH3%2FNlHslEhyJLyWZBTcs8uiHFqFwPHjv5KzTEkd2YDYloGQOG67UF9byirLAmllRycmfJ2ijuX4fLLoAcwC5VfRrktNuBZi%2Fskk2R6R57uNhlIbj7sA7kgSu%2F9v1rIEKCHK1PHKkzcHbmnSFCCmD41gnFKa1srQ9XGAwlNPdkPLTIDftxrDkblNdaACK0TKL1HR%2FvIgvyhu%2F29dwaBYDSlWw7RbeuIFnev5FZRL%2F5qgxFsXtgYxgKNbxVR%2FzFdY%2FwTV9fRC7QUkeaylb6sE0RmUdMAijcpLIWB1AdHNEy%2FLMBCzjdidfGt%2FwyyKwc336mozoTsADWkMdmaQYricLamj0g9rrHhAoKqEjacTRFSSXZxlNtM3t5nouj%2BBCL7N4xUa9zixuspNQw1ihwsEAELLqFKXB%2F%2FP467Cd8Zn2XzDSOfJi8MDLnRRYTWamBHrg4rvqKBLTJe90OrvvmlUqxisdK%2B2F03IU4%2FsZTqapBx4J%2B6YBFcKrEy7e0SHDcsMPKI7KBGf0OYMdVTnK%2B7pC6dVgzJ%2FyO9ba4CP7QfC5z%2BcWZQ%2BFpPYpsmEakddyCIVzZzsc%2B9LVXqa%2F8L%2BVsOjqYBKdd7vPaGR1ItI1wGnoIBhx7jKpuy0hM%2Bcrz20QvSIT9Jai6lER7pwdYVW7dNEuLpPMsrPlJ5juCyi1xaES3jMauV3Rc80baGLxtpfAAHDgwha%2FAsQY6sQEUm9TDzvvJPXw3v0zsSIWM2oIbkPRg1ChgaF0GmpRSicqf3owkgZBdfcpvndM7JJnd7bUNf3O96t0fyqnjG%2FLKecXrc4Y2V0LZzH1nE3PZBx%2BOBkPYTF7u%2F8aASX9HGhHX8wjBnkCgv6XU%2FX5vmvIypErK6vfUDreN6fBPmJzwwBEDYn8gaaERFqTFIaO1r%2BQWudRjIzJ25SKDPNFq4DGLsTGHyaM%2FI5S%2FZkSYpD9FXj8%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20240429T223940Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTY4KPECYSW%2F20240429%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=3ba06431253c1f85a8a15f135345221ee38d3ea298530d1694da19d9a0ee41bf&hash=674cb6fe13ab5c397e45d54b5bf5eb0fe70014b5e51b53aea875cf1860abc8ea&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=073567579390062G&tid=spdf-f843bee2-e76b-4b14-857c-6fd639d24678&sid=b5ab9c59630f274fbf080832ce2175985fe4gxrqa&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=13175852055002075259&rr=87c2ca189f9559a4&cc=us). I can't find the exact video I'm thinking of, but I *vividly* remember a guy talking at SECO's online continuing education thing a few years ago about a dude who could basically pop his eyeball out at will, and how the way to replace it involves a paper clip (to which my answer is no, the way to replace it involves calling somebody who went to school for a hell of a lot longer than I did, and *they* can decide to reach for the paper clip.)
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I know a guy who was mugged and had this happen when he was young. They basically bashed in his head with a bat, robbed him, and left him for dead. He woke up in pain and horror. He put his hanging eye in his mouth to protect it and walked to get help. They caught and prosecuted the criminals. Little good that did him. He had to have quite a few surgeries and a plate. Permanent muscle damage to the eye doesn't allow it to line up correctly with the other one (wall-eyed). It's a permanent disability. Horrible story.
Can some biology brain weigh in on why the eye would have at least 10cm of spare optic nerve length bundled up in there? Seems ridiculous, especially considering how valuable visual information is to survival.
I'm betting it's real stretchy, but no clue. It could be the guy was exagerrating too. I'd never know otherwise.
Could someone explain why a *stretched* optic nerve could retain (or regain) function, while a *compressed* nerve (as in untreated glaucoma) results in permanent vision loss? Edit: Should I repost this as a separate thread if it's too off-topic from OP's original question?
I dunno, I saw this documentary series about animals, and in one, a human hunter going after a rabbit was standing under a ledge and the rabbit pushed a boulder. The hunter looked up and his eyes shot out like 5 feet then shot back into his head before the rock eventually landed on him
What about the ones who can stick their tongue out from behind the eyeball?
I'm a bit confused by what you're saying. The conjunctiva is a transparent layer on the surface, you can see the sclera below it without any manipulation. Isn't it the orbital septum that protects the orbit from the outside?
It’s not fully transparent, you can’t see the sclera as it dives away to make the back of the eye because the conjunctiva is thick there and below it (from a few mm away from the cornea) is tenons capsule, which is another layer of tissue that lies between conjunctiva and sclera. The conjunctiva is the structure that attaches your eyelids to your eyeball and forms the main barrier that stops foreign objects entering the orbit.
Wrong but close! The conjuctiva is a transparent membrane, which the white of your eye (the sclera) sits behind.
Disturbing but useful. Thank you.
> The white of your eye (the conjunctiva) The white is the sclera and it is covered by the conjunctiva which reflects on the inner aspect of the eyelid. https://www.informedhealth.org/grafiken/bindehaut-schematisch_final_enjpg_replacement_image.jpg
I thought there aren’t pain receptors in the eyeball and what we feel is actually an irritation of the eyelid.
There’s plenty of pain receptors in the eye. You can test this by poking your finger in your eye
The front part of the eye is sealed off from the back part by a membrane called the conjunctiva. The conjunctiva runs from the back edges of the eyelids into the top and bottom recesses (inferior and superior conjunctival fornices) and then cover the sclera (white part) to the edge of the cornea (clear part). I've noticed that some pictures skip the conjunctiva for some reason. Here's a quick video describing the conjunctiva: https://www.youtube.com/watch?app=desktop&v=9hCMwptq_cg
A lot of confusion in the comments. The conjunctiva is the clear (ish) membrane that covers the white part of the eye. The conjunctiva "folds" and then connects to the inside of the eyelids, thus forming a "seal". The recessed pocket that the conjunctiva forms is called a fornix and is what keeps water from going behind the eye. Sauce: https://i.pinimg.com/originals/07/5a/3b/075a3b290f47a38dc2f6a209b935c6d6.jpg
So when something like dust/hair goes "behind" the eye and causes immense pain... it's really just up or down in the fold?
Yes, nothing can get all the way behind the eye and stick to the back of your eyeball or anything.
Oh! Thank you for this image, this makes it very clear!
Is the bulbar conjunctiva separate from the fornix? How do you accommodate for movement of eyes? I don't understand the concept of a 'seal' in regards to eyes movements...
You didn't get a good answer yet so here it is: there is is a transparent membrane that is attached to the inside of your top and bottom eyelids. This membrane, called the conjunctiva, covers the front of your eyeballs totally. It looks like your eyeballs are right out there in front but there is the conjuctiva at the top and bottom of your eye sockets making sure nothing gets inside the socket.