Hello Simon. I experience the same. Also a negative afterimage if I look at something for a long time e.g. a television screen or a clock or sometimes the silhouette of a person I am looking at. I find that that along with the trails, BFEP, static, tinnitus etc are much worse if I am in a state of anxiety. I am not 100% sure but it seems to make sense that in an anxious state we are hyperaware of anything that we perceive to be dangerous to us. And because we now know how to "find" these visual disturbances (what to look for, when they're likely to appear, what do to do prompt them to appear etc) it is easy for us to scan for them when we are in a protective state. But generally speaking I have heard that these visual quirks are normal and happen to everybody, but not everybody gets fixated on them and has this anxiety response attached to them, so they do not notice. The best I can suggest is to try to find ways to take your mind off your vision and to bring down your levels of stress with exercise or meditation or whatever may work for you. It's easier said than done but just remember you are not alone