Interesting, something that wasnt covered on your site, although the inverse is. I sometimes get the opposite of the troxler effect, the center of my vision goes "black" while the edges stay visible. The black center gets "worse" if my eyes stay still, and is usually accompanied by a halo of various colors. It goes away after a few minutes. Ive never found a consistent trigger for it, sometimes light changes will do it (going from outside to inside) but not consistently, it can also just seemingly randomly happen