I want to add that I also believe I have visual snow and see after images if I look at something bright.
After having multiple eye surgeries the latest 3 years ago, I have somewhat similar in both eyes and have been to Opthalmologist, Neurologist, and general physician. Nothing was found and told could be migraine, or some damage from the eye surgeries (victrectomy both eyes for RD, cataract repair). Most always its after I wake up in the morning and lasts about 15 minutes. Shimmering spot in both eyes. I do have high health anxiety and I have resolved to ignore and report to the eye md if it gets any worse. I do mention this every time I get an eye exam but nothing is ever found. I have resolved that "it is what it is" and I hardly notice it anymore.
In my non-md opinion, get full physical from your GP to make sure all is well there. Then I would see, if you haven't already, an eye md Opthalmologist. This should rule out some things.