Colours dots move around when using firefox

Green, blue and black dots show on the screen when I use firefox. They move around and quicker when I write or do a search. Sometimes they appear thicker somtimes less. They don't appear in other programs. I havn't found any descripton of this problem nor any remedy.

One example of how it looks. It changes more often when I write someting then when I just watch it:

Its an issue with FF which I have reported to them here

The way to fix this in the interim is as follows:

In the browser address bar enter about:config

accept the warning message and select Show All

Then in the address search bar enter gfx.webrender.all

toggle to false using the left/right icon at the extreme right.

Follow the same route but this time disable WebRender by setting the gfx.webrender.force-disabled flag to trueby the same method,

and then restart Firefox.

A further reference about webrender is located here