Days long afterimage in one eye?

Has anybody else had this? I see this dot shaped darkish-grayish afterimage right after whenever I blink. It's been there for three days. No sign of becoming better yet. Only in my left eye.

Edit: Visited the ophtalmologist. After extensive testing, he couldn't find anything. Will probably try neurology.

Edit 2: The dot gradually became less prominent but my vision got worse in both eyes. Started seeing yellow and dark, and my visual snow became more prominent. After a brain and neck MRI, neurology couldn't find anything. Visited another ophtalmologist, a professor this time. She said I might have had a TIA (transient ischemik attack, aka stroke) and that might have caused it. My regular ophtalmologist disagreed and thinks the Covid mRNA vaccine or medication I use might have caused a contrast problem (I had a severe reaction to the vaccine). I still see the dot sometimes and my vision is messed up in general. No one knows exactly what caused it or how to fix it.