Why do our eyes have to be closed to sleep?

Usually, we close our eyes to sleep . There are 2 primary reasons for this. 1. distracting sensory stimuli (lights, noises, etc.) can interfere with sleep , and closing your eyes greatly reduces visual input. 2. closing eyelids protects our eyes from foreign objects and from drying out during sleep. ---------------------------------------- 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.

erm..not sure what's the answer..

do you know that there are some people who's eyes will open back up while they are sleeping.. its true! some people can sleep with their eyes open, though they usually dont know they do and it is usually the caused by a a problem such a neurological problem, namely bilateral facial weakness.. but it can also be as a result of muscular dystrophy called facioscapulohumeral muscular dystrophy, which is hereditary.. if you wake up often with dry eye symptoms.. you could consider seeing an ophthalmologist to check and see if you should wear eye pads or if its severe.. have surgery.. so they dont HAVE to be closed.. but they SHOULD be! lol

I really don;t know why but I am guessing.I think because its impossible to sleep with our eyes open.When are eyes are open we are continuosly distracted.So for the mind to settle down I think we need to see darkness. :P And I think we need to give rest to our eyes too.That may be one more reason we close our eyes :)

umm....becoz we dont want mosquitoes to stick their tail into our eyes...neither do we want cockroaches playing hockey on out eye sockets!! either way....i have seen an uncle sleep with his eyes open....and it sure look frightening!! like some spirit/gohst or something!! i sure dont wanna look like that1!!! ^_^

i would say yes we do need our eyes closed to sleep. i find it extremely hard to believe that people sleep with their eyes open. think about it: you blink to keep your eyes moist and to push out nething that comes into ur eyes. [[also the purpose of ur eye lashes:to catch dust, particles etc..]] if u slept with ur eyes open, u leave it vonerable to all bacterias, dust, insects and so much more. wouldnt it be gross to wake up with a SPIDER in your eye? ewww. lol. bt yea, i think u have to sleep with ur eyes open. dont kno how to N0T close em wen it comes to sleep. id like to meet that illeged person that sleeps with them open; test their brain waves to c if they're truly sleeping or just n0t answering. =] Britt

Bcuz we cann't sleep with our open eyes. A man only sleeps when he closes his eyes. Listen!!. If u sleep with urs open eyes and a ball comes towards urs face then as u'll b sleeping then it'll straughtly touch urs eyes and........ But on the other hand if u sleep with close eyes then it'll affect only urs skin for few minutes and nothing.

So that they won't dry. It keeps them moist. Now you know. When you sleep, you are blinking with your lids shut. This is true. Now you know.

no, do you know????

its not necessarly true, i have heard dat some ppl can get sp,e kind of operation dat allows dem to sleep wid their eyes open, dont knw if dats true just heard it somewhr

if u keep ur eyes open, ur eyes would b working too much and would b too distracted to go to sleep i think