Google may be our friend, but it also can cause panic. I ascertained that this symptom is a "floater" and while it can mean nothing, it can also mean hemorrhaging, detached retina, potential blindness. There was nothing I could do in the middle of the night. I wasn't sure it was wise to use my eyes to read, so I went to sleep. In the morning the thing was still there, so I called my eye provider and arranged to go in at 2:15. I called my regular doctor to fax over an insurance referral.
The downstairs guard sent me to the 7th floor, which was weird, since normally I go through the contact lens department on 8. On 7, they had no knowledge of me or the referral and I had to call and have it re-sent. I described my symptom, was examined from every angle under dilation, and the doctor said she could see exactly what I was talking about. Nice to know I wasn't hallucinating.
The diagnosis? Posterior vitreous detachment (PVD), very common in older (and especially nearsighted) people. I was told I don't look my age. :) But my eyes act my age. My retina looked OK (for now), and I'm to come back in a month and call immediately if I notice additional floaters, light flashes, or black dots (blood). Time bomb.
There's nothing that can be done about the floater itself and supposedly you get used to it. It's been less than 24 hours and I definitely notice the back-and-forth. It may move down out of the main visual field or disappear altogether, but that could take months.
The good news is while I was inside, the referral came and it authorizes 6 visits. I still need to have my annual comprehensive eye exam/refraction, and will arrange that after the follow-up.