https://upload.wikimedia.org/wikipedia/commons/9/9c/Dyslexic...
Say I was reading the line "...as well as other perceptual tasks." I would insert words from inside the "circle" so it would appear to me like "23 other reading tasks" or something (often times it will make no sense, which is my cue that I need to re-read the whole thing).
Other times I might just read a word like "presidental", then look back at it and suddenly it says "prudential" as if it changed when I wasn't looking at it (and I'd swear I knew it said 'presidential' the first time).
Writing and typing are a whole other can of worms that I won't open here, but suffice it to say that I've never experienced the dancing letters like in the OP.