An interesting post, Tero, particularly your experience with the use of aspirin in reducing or terminating visual disturbance. I've heard of others who have had the same success with low-dose aspirin (you didn't say what dose you took).
This begs the question: if taken regularly, could low-dose aspirin be effective in reducing the incidence of visual disturbances or even eliminating them altogether? A quick Google shows one current medical trial taking place but I couldn't find any published results.