About an hour ago, as I was going through conversations and threads here, I started having trouble reading the screen. It was as if there were three or four rows of wavy lines moving from the center of the screen, upwards and to the right. This is similar to what some people get with a migraine, I think, except that I didn't have a headache at all. Since I've never had a migraine, I don't have a lot more to compare it with. I tried eyedrops but, while they made my eyes feel better, as they always do, they didn't do anything for the visual artifact. This lasted about forty or forty-five minutes, during which time I gave up trying to read the computer screen and went for a walk. When I returned, everything was back to normal.