[d4mi3n]

No night shift, for what it’s worth. Another commenter mentioned astigmatism, which I do have. I was not wearing my glasses at the time.

Curious to see if anybody with expertise on the topic of optics or visual perception chimes in with some insight.

[kerpotgh]

Interesting, I have astigmatism so I tried it without my glasses and with both one and two eyes open at different angles and I still see the illusion (with no change in intensity of the “bobbing”)