Do you have myopia or hypermetropia? I've had myopia since I was a little spermatozoa (I was the fastest one because I was trying to get away from the bullies), and growing up, I had to wear thick lenses. I noticed that looking at things from different viewing angles from within the area covered by the glasses produced refractory effects. Depending on the quality of the glasses, you get that to varying degrees as the manufacturers will create it in such a way that the best area for viewing is right at the center.

Try this: Instead of moving your head from side to side, try fixing your eyes on the editor and move your head back and forth with your ears as the axis of rotation (like nodding). Do you see the movement occur as you near the edges of the glasses?

It's only after I got those thinner lenses (that cost more, so I wear them for years) that I noticed that what I had been experiencing wasn't actually what the world looked like.