That might be the reason you see wheels appearing to go backwards.

This is most noticeable in movies and on TV with wagon wheel that have spokes.

BA explained it fairly well.

A 16 mm movie camera runs at 24 frames per second and a TV camera photographs at 30 fps. A film camera has a shutter that is closed about half the time and open about half the time as the film moves inside the camera while the shutter is closed, stops while the shutter is open, then moves again while the shutter is closed. A TV camera has an “electronic” shutter that usually jumps from one video frame to another with no “closed shutter” time.

For film fps to be compatible with TV fps, some years back they invented a video device that photographs every 4th movie frame twice, and that converts films to 30 fps for TV. You can see that by still-framing a movie you record off TV, then advance the film one frame at a time.

If you have a wheel with four spokes, and the wheel makes 1/4 of a revolution while a movie camera shutter is closed, you will see the wheel as not turning at all, even though it is turning. Let’s say the shutter is open always when two spokes are vertical and two are horizontal. It will appear that way when you view the moving film and it will appear that you are seeing the same spokes always in the same horizontal and vertical positions. But actually you are seeing different spokes in the different positions. If the wheel doesn’t quite make a 1/4 turn during filming, then the spokes and the wheel will appear to be turning backwards.

Let’s say we take a four-spoke wheel and we paint the right horizontal spoke red, then we turn the wheel clockwise and photograph it with a film camera. If we turn it 1/4 turn in between each film frame, we will see the wheel appear to not turn at all, but we will notice that the red spoke seems to move around the wheel clockwise. The red spoke will first be seen as being at the horizontal right, then the vertical bottom, then the horizontal left, then the vertical top, then the horizontal right, etc. Of course, that reveals that the wheel is actually turning.

If we slow down the wheel a little, so that it doesn’t quite make a full 1/4 revolution turn while the shutter is closed, the wheel will appear to be turning backwards, however, we will notice that the red spoke goes from being horizontal right, to being almost vertical bottom, to being less than almost horizontal left, to being much less than horizontal top, to much much less than horizontal right. So that tells us the wheel is actually turning clockwise, but not quite 1/4 turn per movie frame.

Your eye twitching might also cause a similar effect when you see wheels turn in sunlight.