system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is actually happening when you scratch your eyes too hard and you get a sort of lightshow behind your eyelids? What causes it?
gpt
Pressure on your eyes puts pressure on your optic nerve.  Putting pressure on nerves makes them send signals that aren't really there. The occipital lobe of the brain (the part of the brain that controls vision) gets this signal and says the equivalent of (In an Italian accent) "Woah, woah, eh, c'mon!" to the rest of the supratentorium and this is perceived as light.

note: the brain doesn't actually talk in an italian accent.