To be clear for anyone else that may read this, any sudden visual impairment warrants an immediate visit to the ER. Even though many problems will resolve themselves, there are plenty of others that can cause permanent vision loss if they aren't treated properly.
I'm not a doctor, but I've had similar symptoms unrelated to VR. After several tests (including an MRI), I was advised to wait and see if the problem recurs. Given how long you've been asymptomatic, just wait and see seems like a reasonable course[1]. On the other hand, my symptoms did come back after a while, and it sounds like that VR session put more strain on your eyes than I've ever subjected myself to.
[1] I am not a doctor; when in doubt, talk to anyone w/ a medical license
B) I can't resist: https://www.youtube.com/watch?v=qaz2hxZLycY
It's not an uncomon effect for any close focusing to distort vision temporarily, especially if your eyes are tired. I visited an opthalmologist last year because of persistent ghosting at night, and it turned out to be from reading laying on my side in bed causing one eye to partially cross but not fully uncross until morning.
It happened when I attempted to use the Rift with Portal, which at the time had very primitive Rift support. The game had a calibration mechanism which adjusts the field of view for each eye independently, as well as the "left-rightness" of objects as they recede into the distance.
I fiddled with the calibration for a little while, but everything looked pretty muddled. Suddenly it all came into focus, mostly, and I played the game for an hour or two. Which is to say, I stumbled around in this weirdly-calibrated world.
When I took off my Rift, I was astonished to find that I was cross-eyed, and couldn't uncross them. I tried closing my eyes, focusing in the distance and then back, etc, to no avail. After a few hours I gave up and went to sleep.
I woke up fine. It was one of the strangest experiences I've ever had, and I was wondering if anyone's experienced a similar effect.
EDIT: Interesting. Apparently the answer is "No, no one else has experienced this."
I should clarify some details. This was several years ago, back when Rift support was in its infancy. The only thing I remember is that there was some sort of program designed to inject Rift support into games. Back then, Mirror's Edge, Portal, etc didn't have Rift support, but using this program, you could hack it to work.
I think what happened is this: Point at the ceiling, then bring your finger close to your nose. Keep focusing on your finger. There's a distance where you have to cross your eyes in order to continue focusing on your finger. Bring it a little closer.
I'm pretty sure that's how I had the calibration set up. And I played like that for a couple hours, which caused my eyes to adapt to that situation. Hence, cross-eyed vision.
I've played many other games with no problems, so it was definitely a product of the bizarro calibration. It'd probably be a bad idea to try to replicate this, but there were no lasting effects.