The Raven's Roost

 You don't see "magic eye" 3D things around much anymore, but I really liked them when they were popular. I was actually pretty good at seeing them, I think mostly because I'd come across a short article in Omni about them, with an example you were supposed to write in about. I remember it specifically seemed designed to weed out fakers, because it asked, "what is the five-letter name of the animal in the puzzle?" and the answer if you could see it was actually "wasp," which is, of course, four letters. But I digress. The useful tool it featured was a couple of black dots to focus on until they seemed to be overlapping, which would let you know that you were focused properly for viewing the magic eye thing. I found it easy to do. My Mom even bought me a whole book of those things once, which was a lot of fun to go through. Most of the images were animals, I think it was the theme of the book. Anyway.

I seem to remember well before that, even, doing a similar eyeball trick as a kid. I had insomnia a lot, and like most kids with insomnia was told either that I was asleep and dreaming I was awake, or that I didn't have insomnia I just didn't want to go to bed like I'd been told. One thing I used to do to pass the time after lights out was basically to cross my eyes and focus inside my eyelids in a certain way that made me feel like I was floating. 

This morning I remembered that the two are the same. That very same focused but unfocused state.

Also "magic eye" is technically an autostereogram, which is a hell of a good word.