I am having the exact same issues. It seems to happen when ever I look at glowing objects or in dungeons. I've made an album of some of the screen tears...
I only noticed this happened after the last big update. Please can you address this, it happens so often I'm considering not playing until it fixes. It makes it difficult to see things I am attacking at times.
As someone who wanted Zenimax to put a proper full screen mode into the game I was pleased to discover that they finally had with the latest patch. I also noticed graphics tearing after the latest patch and it turns out the ESO now defaults to full scree mode; it feels a bit of a retrograde step, but going back to full screen windowed mode sorted these out for me.
I am one of The Great Mediocracy, those whose role in life is to provide the baseline by which The Few deem themselves Great.
I have seen bird images when I fight NPCs that cast those green shadow birds at me. I get this like exclamation shadow on my screen... How do you put an image into your comment? It keeps telling me my files are not allowed.