What does it mean to be seeing stars?

Seeing shimmery dots: Seeing stars means seeing shimmering spots or dots. It can mean a problem with the eyes, if one has no reason to see shimmering dots (didn't just stare at a bright light, didn't get caught by a camera flash, is not squeezing his eyes tightly, is not dizzy or fainting). If the symptom stays for more than a minute, or is a repeating symptom, an ophthalmologist can do a full eye examination.

Retinal light flash: Seeing stars is the expression for the light patterning seen when an eye is struck. The retina only has nerves of vision and so when any stimulus -pressure, temperature, contusion - strikes the retina, it registers light. Boxers are familiar with this.