But under certain circumstances, sometimes I experience an oddness when my eyes track motion. I'd describe it as watching something and imagining it as individual frames of film, and every so often the frames don't run together in a smooth animation. They look blockier, like when you see an infomercial that's been badly edited and has a shaky camera. But it's pretty rare, I'm just not sure what causes it. I've noticed mainly if I'm watching TV and there's a broad horizontal pan, and it doesn't always happen.
Sorry it took me so long to get back to this.
That's an interesting situation.
There are really two main types of eye movements: smooth pursuits and saccades. Smooth pursuits are just just, you're tracking something and the eye moves in a fluid motion. A saccade is when you're actively trying to move your eye to a specific location (as you look into a street for oncoming cars, or as you read across a page) and tend to be jumpier.
So, if we're talking about something that shows up while you're following something, then that would be a smooth pursuit disorder, but if this is showing up while watching TV and you're actively trying to look at another portion of the screen that would be a saccadic disorder.
TVs these days are often big enough (fancy term: subtend a large enough visual angle) that we do have to perform more eye movements than in the past, and they're often crisp enough that our brains can get tricked into thinking that we're following actual objects rather than just looking at different parts of a static screen. In the absence of more advanced testing, I'd guess that what you're noticing could be moments where the illusion is broken and your eyes are making jumpy saccadic movements from one part of the screen to another rather than conducting smooth pursuits.
Of course, if you notice this when not watching TV I'm completely off here. I was never very good at diagnosing by text.