Not sure what you mean by the question but you might like to look up the word 'Turiya'. . .

To quote the eminent philosopher John McCrea:

When you sleep,
Where do your fingers go?
What do your fingers know?
What do your fingers show? — When you Sleep, by Cake

Reality goes on for those who aren't asleep. They might look at your unconscious body and count the hours.

And so we'd expect, when the earth loses its last sleeper, that the universe is deaf, dumb and blind to itself -- like one asleep.

I wonder what happens to reality when we sleep. — Cidat

What are the grounds to "wonder what happens"? Sleeping is real, ergo (at least that aspect of) "reality" happens.

If you are very good, and say your prayers, then Jesus will protect you while you sleep from all the goings on. You would not believe what goes on while you sleep...

“From ghoulies and ghosties and long leggedy beasties and things that go ‘bump’ in the night, Good Lord, deliver us!”

I wonder what happens to reality when we sleep — Cidat

Much like in the movie Dark City, all the buildings get rearranged and everyone's identities and memories are altered.

Well according to some interpretations of Hume, it no longer exists, until it can be observed by a human to given it existance.

Don't we experience change while we're asleep? Reality must keep track of all other organisms' state and location.

The majority believe so, yes.

Reality must keep track of all other organisms' state and location. — Cidat

It would be nice if reality did keep track of everything, but "reality" does no such thing. It can not because "reality" is a concept, a mental object--a rather big mental object.

We are not entirely out of touch with the world when we sleep. Our brains are busy doing something (???) 24/7. Your brain "puts you to sleep" and it "wakes you up". They can keep track of time well enough to wake you before your alarm goes off (unless it has decided to sleep through the alarm).

Some animals that can't afford to have both sides of their brain sleeping at the same time put the left half of their brain asleep and keep the right side awake -- then switch.

If you were the only organism on earth, your question would be profound, Fortunately, the earth is full of creatures that sleep, perchance to dream.

We are not entirely out of touch with the world when we sleep. Our brains are busy doing something (???) 24/7. Your brain "puts you to sleep" and it "wakes you up". They can keep track of time well enough to wake you before your alarm goes off (unless it has decided to sleep through the alarm). — BC

Yes. It was striking the first time I underwent anesthesia - the difference in time sense between waking up from sleep and coming out of anesthesia.

Anesthesia really is different than sleep. Does one feel "rested" after anesthesia? I haven't felt "rested" afterwards. It was an "empty experience". I woke up with surgical wounds and discomfort but no recollection of the surgery. But then, I quite often wake up in the morning with no recollection either -- no dream memory, no sense of the night having sped by. (On other occasions it seems like a lot happened -- memory of complicated dreams, waking up several times, full bladder, etc.

One thing about waking up from anesthesia -- there has always been a nurse on hand when I've woken up. I don't know what it would be like to wake up in a room alone in the dark, say. One would have to put 2+2 together one's self. Might be scary.

We typically sleep for around 6 hours every day, but I wonder what happens to reality when we sleep. Do we wake up in the moment after we fall asleep / lose consciousness? — Cidat

Reality keeps on existing as it has been. To the sleeper, the reality disappears, as he/she enters either into a dreaming state or total black out (unconscious state).

When waking up, the sleeper's memory will bring the person back into the normal reality that he has been sleeping, not newly born or thrown into the world at that moment.