I couldn't figure out how to quite word this so sorry if it has been asked before, but I would like help with a weird glitch I am experiencing.
So I've been working on this shape (I hope to mirror later on) which I crafted out of a cylinder. I want to get into good habits, so I worked hard to get all the vertices and edges just right, no simply overlapping anything. I double-checked for duplicates and I do not THINK there are any but I could be wrong. When I move around the scene I see these weird distortions.
See the mangled line at edge of screen.
But When I double check my render everything seems fine.

When I unhide the other object the effect gets worse, but still it doesn't affect my render. I have checked as best I can for duplicates, but I am afraid the problem might be in some obscure viewport setting, which is more of a maze for me. It doesn't help that I don't know how to word this issue.
Any help at all is greatly appreciated!