Hi, I have had so many weird visual disturbances. I experience ocular migraines frequently, which start as a flash or blind spot like you describe. Then it progresses into a weird moving zig-zag pattern that eventually floats out of my field of vision after 20 minutes to an hour.
Just yesterday I saw this green ball of light whenever I closed my eyes, in the same spot each time. Later that night I saw a weird flash like you described every time I blinked. I went to the eye doctor yesterday and my eyes are perfectly fine... apparently my brain is too because I had an MRI in November.
Sometimes weird visual things happen. I have been seeing random colorful dots for months now. I'm not even going to go into all my visual symptoms! Anxiety can do really weird stuff to the eyes. Sometimes, people just experience weird visual things for no reason... I know I do. You could just be one of those people.