I think it happens most after I go from a dark room into a room where I turn the light on. After going back into the dark, I get this flashing circle of light. Sometimes I get it after long stretches of looking at the computer monitor.
The circle seems to be pea sized with an irregular surface. It flashes, seems to explode into light and then disappears. Sometimes it is less defined as a circle and the light is more jagged but it always seems to start in the middle of my left eye. It happens if the eye is open or the eye is closed but is more apparent when the eye is closed. It is cyclical, it will pulse, explode and then disappear. It repeats the whole process after about 6 seconds. After a few minutes it goes away.
somewhat worried.