Dark Spot in Peripheral Vision for seconds, but NOT floaters
Last week, when I was working on the computer, I noticed a solid, round dark spot appearing abruptly at the bottom of my left eye. It appeared and disappeared right away and I had a subtle sense of discomfort, while alarming, it did not cause me to go to the doctor immediately.
A couple nights ago, also when I was looking at the computer, I suddenly notice two black spots abruptly appearing in the left corner of my peripheral vision (and it also felt as though it was in the left eye only, like the first time). The two black spots appeared one right after another, and overall only lasted 1 second, maybe 2 seconds, at most. During this very short period of time, it was almost as though that part of the vision was blacking out, and I also felt extremely dizzy and out of sort, almost like I was about to faint.
So the second day I made an emergency appointment with an ophthalmologist. He did the eye exam (I don't know the names of the exact procedures but I had the visual field test, the dilated eye exam, etc. and they were like the procedures of an annual eye exam). The results came back fine as in he couldn't find any abnormality. It showed no signs of retinal detachment. My blood pressure was normal (so not caused by high blood pressure). I have no known history of diabetes, etc. The visual symptoms was extremely brief and I didn't have a headache before or after. The glass prescription for my nearsightedness is the mildest possible and hasn't changed since I first got it in the summer. The doctor himself said my symptoms doesn't fit the description of anything he was worried about before seeing me. I did a search online and while a lot of people see "dark spots" that are floaters, my symptoms don't exactly fit the description of floaters either. So right now, there is basically nothing I can do except to monitor it and it has caused me a lot of anxiety.
Anyone has similar experiences? What was the prognosis and diagnosis? What was the treatment?