I am with Phill in this issue, as some years ago also I started seeing flashes and it was the retina gone loose. First the retina of my right eye was fixed by laser surgery, as it had gone loose because my head had been hit - and two years after that the retina of my left eye had to be operated for the same reason, though this time the retina had a hole because of a typical injury caused by strong near-sightedness (no v*olence in that case). Without surgery I would be blind now... So I recommend checking one's eyes just in case, though seeing flashes/spots may also be related to anxiety/migraine.