Why must we close our eyes to sleep?

Although we almost always sleep with our eyes closed, people can and do sleep with their eyes open.

Sleep is generally defined by the presence of certain types of electrical activity in the brain. When people are awake, the electrical activity of their brain, as measured by an electroencephalogram, is desynchronized and of low amplitude. As a person enters sleep, the pattern of their brainwaves changes from low amplitude, higher frequency waves to higher amplitude, lower frequency waves. Additionally, sleep is subdivided into different stages. These stages are defined by the frequency and amplitude of the electrical waves being generated by brain activity, and are also related to easily how a person can be aroused by an external stimulus. Finally, there is a separate stage of sleep called rapid eye movement (REM) sleep, which is characterized by a more "awake" looking brain wave pattern, eye movements, and dreaming.

Usually, when we sleep, our eyes are closed. In my view there are 2 primary reasons for this. First, distracting sensory stimuli (lights, noises, etc.) can interfere with sleep, and closing your eyes greatly reduces visual input. Second, closing your eyelids protects your eyes from foreign objects and from drying out during sleep.

That said, there are instances in which people may be asleep with open eyes. One good example is sleepwalking. Usually, a sleepwalker will initially get out of bed and walk around the room with their eyes open. As the episode continues, their behavior can get very complex. They can avoid objects, go to the bathroom, even clean the house. All during this time, an electroencephalogram would indicate that this person is completely asleep. I would imagine you could also see this sort of phenomenon in someone who had been sleep deprived for a long period of time. They might at times appear behaviorally awake when their brain wave patterns are sleep-like.

If We Close Our Eyes

at one point in time we could probably sleep with our eyes open, but because of evolution, humans have probably adapted to sleeping with our eyes closed. kindove like horses, a long time ago there eyes were in the very front of there head. As they developed monaturallyapredatorsors, there eyes grew apart. Hope this helps.

Probably to keep your eyes lubricated and to block off external stimuli (light) that could interfere with sleep.

To keep your eyes open it all takes energy. When you sleep your nervs start relaxing and the energy slows down which makes your eyes to close.

We close our eyes to help us relax and eventually fall asleep, if our eyes opened in our sleep it would disturb the brain and wake up.

You don't HAVE to close our eyes, some people can sleep with their eyes open. But your eyes will dry out and that would be very uncomfortable.

We close our eyes because the stimulation of the world is too great sometimes to fall into sleep and the eventual REM (rapid eye movement) stage.

although I did once know someone who fell asleep with his eyes open. it's rare.. but does happen

In addition, your eyes need constant moisturizing..

My dad sleeps with his eyes open some times. Once I had called 911 because I though he was dead. (He normally snores loud but this time he wasn't and he was sleeping sitting up in the couch.) So my freaking out was justified.

because you have your eyes are open all day and they need to rest so they close when you go to sleep.

to relax your eyes too. the state of relaxation that the body goes into while sleeping would not allow us to function. I love to sleep!! happy holidays!!