My doctor asked some questions, didn't seem concerned, and told me I had a condition called acephalgic (painless) migraine, ocular or optical migraine, or scintillating scotoma. I like the last name best but tend to use the second. "Not to worry," she told me. "Just enjoy the light show." I don't worry, but I can't say I enjoy the light show because they generally come when I'm reading or at the computer.
They are more common in the spring and in the autumn. They tend to come in clusters, sometimes three in two weeks and then none for several months. They last for about twenty minutes and when they go away, sometimes I feel tired or "funny" -- I can't be more specific about "funny." Just "strange."
Scintillating scotoma is a bit of an annoyance, and that's all. I'm thankful I don't have full-fledged migraine headaches -- my mother had them and one of my children has suffered from them since the age of six.
I had one last week. Yesterday I had one in the morning while at work and another when driving home. A third one struck about an hour after dinner. I was sewing and I imagine my concentration was impaired because I made the same mistake on three blocks (yes, I know, I'm a big fan of consistency!). So I gave up and did something else. And went to bed earlier than usual.