Small Graphical Bug

I'm unable to post a screencap of this, unfortunately, as it's a graphical bug that flickers constantly. It's been there for a while, and I wonder if anybody has noticed it yet. When selecting a hostile or friendly turret, the secondary bar below it's health bar has a flickering white triangular shape all the way to the corner of the screen. I was just wondering if this happens to anybody else, or is it just me? Granted, it's not what you'd call a game breaking bug or anything. It's just something I've been noticing for a while. I know it can't be because of my PC's specs... because it runs League perfectly, even on really high graphic settings. Nobody what I change my settings to, the flickering is still there.