We all know that we have to close eyes while sleeping.
But, why it is so?
I mean to say that eye is just like an organ of sense like nose, ear or skin. We use to hear by ears, touch by skin and smell by nose. And, in the same way, we use to see with eyes. The methodolgy for all the sense organs are the same.
But, we do not close either nose or ears before going to sleep. But, why it is essential to shut down the funtion of only eyes before sleeping? Why can we not sleep with open eyes? What is the problem?
Even our mind does not shut down itself during sleep, otherwise we would not be able to see the dreams. But, why the case of the eyes is the only exception?
I would like to know if any philosopher/biologist ever said anything about it.
nice picture, sanjay. it looks like it was meant to be a serious face, but it also kind of looks sassy.
It’s an interesting question.
My guess has to do with blinking. We need to blink, right? to clear our eyes of stuff, to keep them from drying out, and to avoid debris and contaminants. Perhaps the part of the brain that controls blinking isn’t active when we sleep so maybe that’s why our eyes just remain shut.
Maybe closing the eyes for sleep has other benefits as well. Perhaps it creates a darkness that is favorable for human sleep. I don’t know.
I recall I have seen people asleep with their eyelids halfway closed – their eyes still slightly visible.
Again, it is a pretty cool question. I wonder what the reasons are myself.
The pineal glan produces a hormon, Melatonin, which regulates, amongst other things, the sleep cycles and the depth of the sleep. The production of Melatonin is stimulated by the absence of light, i.e., when the retina of the eyes detect light, its production is inhibited and in darkness, when the eyes are closed, its production is stimulated. Without Melatonin we could not sleep at all; closing the eyes during sleep is necessary to survive. Sleeping with eyes half open is usually regarded as a sleeping disorder.
Fuses’ answer is right as well. The “blinking-system” doesn’t work when we are asleep and closing the eyes is a protection against drying out and debris.
To be honest, i very seriously tried not to look very serious.
I just cannot help it but my face looks very serious, especially in the pictures. But, in reality, i am a very sensitive person, far more than an average. But, my feelings does not reflect much on my face. It remains almost the same all the time.
Well, i do not think that blinking has much to do with this.
First of all, i want to thank you for sharing that information. That certainly helps. I myself also tried to look into the matter by the help of the information given by you.
This is true that that the absense of light helps producing Melatonin by the Pineal gland, which is located in the brain. And, that happens at every evening. Having said that, Melatonin does not answer precisely what i am asking.
Let me explain.
The question is not that what causes drawsiness but why we cannot sleep with open eyes.
During the evening time, as the light diappears, ratina send signals to the brain and Pineal Gland of the brain starts releasing Melatonin and we use to fell sleepy. It is fine up to here.
But, the job of Melatonin is done by now and we should be able to sleep, whether our eyes would be closed or not, because it is already dark now, thus, even opened eyes would not stop the production of Melatonin. But, we know that would not happen.
Secondly, wiki says that it is only blue light that resists Pineal gland from producing Melatonin, not all light.
So, it is only blue light, below the wavelenght of 530 nm, that is our cause of concern. Right.
Now, what will happen if we try to sleep with open eyes but wearing such glass, which does not allow the light of below 530 nm? Acoording the theory, that would not restrict the flow of Melaonin and we would be able to sleep with open eyes. But, can that happen in reality?
Secondly, what will happen if we try to sleep in such a room with open eyes, which is totally dark (that is not a very difficult thing to arrange)? Going by the use of Melatonin, we should be able to sleep in such room with open eyes. But, can than happen in reality?
Melatonin is not the answer of my question. There must be someting else which compell us to close our eyes before sleeping.
I have a basic idea of what happens at that time, but i want some help from one of the members of ILP to crosscheck myself.
I want to humbly request Maia to join this thread. As we all know that her case is unique and perhaps her experience would throw some light on the relation of eyes and sleep.
I want to know how she feels drawsiness and fells asleep. I am sure that would help a lot in understanding this issue.
I would feel highly obliged if she join the thread and answer some questions.
I am PMing to her also.
It’s common in healthy people to see partially open eyes during sleep, I see this sometimes with kids and it usually doesn’t cause any problems.
There’s a condition called lagophthalmos which causes people to be unable to close their eyes for sleep because of poor muscle control. They usually develop eye irritations form poor lubrication.
Other vertebrate animals it’s also necessary to maintain the eyes lubricated… except for fish, I guess their eyes stay moist enough
You can probably put this under a evolutionary mechanism all the way back in vertebrate development. I reckon that individuals unable to keep their eyes from being constantly irritated from poor lubrication were probably at a serious disadvantage.
I am not asking that one should stop blinking either.
If one can keep his eyes lubricated enough by blinking while being awake, why he cannot do the same during the sleep?
Blinking is not will-induced action but use to happen without invoking thinking process, much like breathing.
You might want to consider that only the eyes have a “turn-off” mechanism. The brain seeks calmness and solitude for sake of sound sleep and does many things to produce that (avoiding loud noises or too offensive of odors). If it had an “ear-lid” and certainly a “nose-lid”, I suspect that it would close those too. But the eyes required a lid for a more significant reason, so the brain merely uses what it has on hand.
And, i think that it is leitimate question why sleep entails complete turn-off in the case of eyes only, but not other sense organs.
No, James.
This does not seem to be the case of using what is available at the moment.
Firstly, if that was true, humans would have evolved having some lids to ears and nose too.
Secondly, It is known fact that light music does not cause trouble in sleeping. On the contrary, it acts as a catalyst.
In all cultures around the would, there is tradition of singing lallbies while making the children sleep. And, besides the tradition, it actually helps.
Thirdly, if you ever noticed and all mothers here would be aware of the fact that sometimes mother even stroke the child in a rhythmatic manner on the head or back to make him sleep. It means that his touch organ (skin) is continuously in action, but instead of causing restraint, it helps the sleeping process.
This phenomenon can be seen in the adults too. Many people cannot help but start napping as soon as they sit in the bus or train, even when they are sitting not lying horizontally. They would not be still, their bodies would be moving here and there but still all that does not restrict sleeping. But, as soon as it comes to eyes, all disturbance is prohibited. One can use all his sense organs mildly except eyes.
The first thing that i want to know is that how you draw reference to the things/people? What is the root of your mechaniscm of remembering things?
Let me elaborate it further.
In the case of persons having vision, the first referance to the remembrance is the very picture of that thing in the most of the cases. Means, as soon as i think of my died mother, before anything else, her image comes to my mind, no matter in which context i am remembering her.
But, i want to know how you do it? What exactly comes to your mind first of all, when you think of anything?
Maia, the question is bit tricky. You have to pay attention to the working of your mind before answering it. You may take your time.
With people I know, it is their smell that I think of first, which is always unique and distinctive. Followed quickly by their voice, of course, but smell is first, and cannot be disguised. With inanimate objects, it is their shape. If you just said a random name of an object to me, say, scissors, the shape would immedately pop into my mind, along with texture, and so on.
You believe that the entire process of evolution is founded upon the need for sleep? That there is no reason for anything to have evolved in another direction, a direction of greater importance? Come on, now.
I said that it was “calmness” that the brain sought. That would include gentle soothing motion and sounds because they inherently obscure more disturbing sensations … into calmness. People would have very little trouble sleeping with a very low soft level of light as well if they hadn’t become accustom to less, but they would still have that dehydration issue. Rhythmic lighting can put you to sleep as easily as stroking sensations.
I never said that. I am not sure from what you got that impression.
I am merely saying that sleep is a process of daily use, thus, if other lids were necessary for it, nature would have been made provisions like eyelids. It does not mean that it is the sole aim of the evolution.
The real issue is shutting the eyes, not the soft or harsh light. I am not sure that rhythmic light would have same effect as rhythmic stroking. It is the matter of verification.
James, as I said in my reply to phoneutria, blinking is much like breathing. It oprates in both ways, intentionally and automatic too. We need not to think for blinking so a sleeping person also can do that, just like the case of breathing.
Secondly, in you look carefully, even soring of eyes takes some time to reach any uncomfortable level. Means, soring of eyes is not an obstacle in the intial period of process of falling asleep. The trouble would come after some time and eyes can be shut at that moment.
But, the fact of the matter is that the process of falling asleep cannot be even initiated without stutting the eyes.
The second question is that how you make point of reference to distant things, which you can neither smell, hear nor have any idea of their shape.
Like, what comes to your mind first of all, when anybody talk about ILP, or such a person or thing which you can never have interacted in any way in person, like members of ILP, with whom you interact through net?
