phosphene
/ˈfɑsfiːn/
noun
- A flash of light or color seen in the eyes without actual light entering them, often caused by pressure on the eyeball or by stimulation of the visual system.
- When I rubbed my eyes, I saw a brief phosphene of swirling colors.
- Astronauts sometimes report seeing phosphenes in space due to cosmic rays hitting their eyes.
- A sudden phosphene can be startling, but it is usually harmless.