Are they black spiders? wiry and jumpy? ( look like they are made from a bale of wire? ). And also "webs" that float around? And do your eyeballs swell a lot?
I had those at the very beginning of my mercury problem. I had an ophamologist tell me that can be a sign of retinal detachment. Not to scare you, but you may want to check that out.
In my case, I think it was due to my eyeballs swelling up ( I even got color changes! ) before I got my fillings out and deficiencies in vitamins as my digestion was terrible at that time.
It may or may not be related to your mercury problem, I'm by no means qualified in any way to tell you it is or isn't. But you may want to check it out.
Just for your info, I used to get sleep paralysis too. Entire body. After lots of chelation, I don't seem to get it anymore.