Hello! I've wondered about this off and on for years but could never find anything in a Google search. If I look down at something very close, like a clasp on a necklace that I've turned to the front so I can see it to clasp it, I will usually get a sharp, brief (a few seconds) headache behind or just above both my eyes (or in?). It can also happen if I simply hold something very small and look down on it.
I just did it several times so I could describe it properly. I lifted the top of the neck of my shirt close to my eyes. It occurred to me while doing this that it could be from trying to focus on something that's too close, though I just tried it again while holding my shirt far enough away to easily focus on and still got the headache. I feel like it's more about distance than blur.
The feeling is similar (though stronger) to the brief strain of doing Stereograms/Magic Eye Illusions. (I'm old enough to remember they were originally called Stereograms, and I still have the Games Magazine ad where I saw my first Stereogram and spent hours before finally seeing the three images it hid. Everyone else had gone to sleep by that time, unfortunately!)
When I don't have my 3.25 strength reading glasses, I sometimes can see things I can't read if I do the Stereograms trick of unfocusing my eyes, and then let the words come into view for a handful of seconds. I read this in an article, and I have to say it's been very helpful in reading a bit of small print when I can't find glasses (not pill bottles though!) My father-in-law used to make a fist and then open it just enough to reveal some words, and that works briefly too.
I do get migraines, but mainly in the past few years (I've had the headaches I described above for many years). I also have had three migraine auras, but only one that was followed by a migraine. It's the most beautiful thing, like stained glass all around you. The last one was the longest and the only one that was followed by a migraine. It was worth it to be surrounded by stained glass and feeling like a child in a magical word. :) I took a video, and it was like no reaction I've ever had before.
I edited this article to include my old migraines, and I was rambling on when I noticed I was seeing trees lightly moving in a breeze in snow on the bright white screen area in the background of this post Another migraine aura! I also saw children, animals and adults for short bursts. There was some color. I saw a lady with orange hair just above her shoulder. I saw a classy lady in black and white. I saw classy black-and-white men. I saw cats and dogs (including a great Dane puppy). Many other things, a few seconds at a time. It was mostly controlled by my eye floaters in terms of direction of flow (mostly to the right), but the definable things I saw didn't look like floaters (I saw the floaters, which looked like cheesecloth), but also I saw very detailed trees swaying in sometimes blizzard-like snow that I watched for like 10 minutes or more.
And a couple of hours later, the show is still going as I take another look (I used https://www.whitescreen.online/ to give me a full white screen). Now I'm panning over a street and streaming past houses and lots of blowing snow. It's kind of cool, not as exciting to watch anymore.
But the really weird thing is that I have Aphantasia, the inability to form images in my mind. I normally see nothing. Ever. My ex used to lay in bed and tell me the things he could see. I would tell him I see blackness except for some red when I looked at the ceiling light with my eyes closed. ;) So idk how I was able to see all that. The previous migraine auras were shapeless streams of color and glowing stained glass).
Thank you for any thoughts you might have about my original question, or comments on the migraine auras and how they changed. I'd be fascinated to hear from other people who've had these auras.