Eyes & space · 60 s
The colors you see when you rub your eyes
You can see without light.
You’d think. You’re just seeing stars. It’s actually your retina getting fooled.
Actually. Press on your retina and its cells fire anyway. Your brain can’t tell the difference, so you see light. These are phosphenes.
The twist. On Apollo 11, astronauts saw flashes with their eyes closed. NASA traced them to cosmic rays shooting through their eyeballs.
How sure? This follows NASA’s explanation. New flashes with your eyes open can mean a retinal tear, so see an eye doctor right away.
Sources
What the video says
Rub your closed eyes and colors show up, even though no light can get in.
People call it seeing stars and move on. It's actually your retina getting fooled.
Your retina turns light into nerve signals. Press on it and those cells fire anyway, and since your brain can't tell the difference, you see light. They're called phosphenes.
Sneezing can do it too, and so can standing up too fast or moving your eyes very quickly.
The strangest version happened in space. On Apollo 11, astronauts saw flashes with their eyes closed, and NASA traced them to cosmic rays, tiny particles that shot through their eyeballs and set off the retina.
In the dark, crews saw one about every three minutes.
New flashes with your eyes open can mean a retinal tear. Get that checked right away.
Astronauts flew to the Moon for this light show.