What causes the weird colours and patterns that you can see when you run your eyes?

If you've never done this before, close your eyes, and rub them with your hands until you start seeing all kinds of random shapes and colours... it's kind of like a kaleidoscope, and almost seems computer-generated or electronic...





I used to do it all the time aa a kid, and still do it now sometimes when my eyes are tired. Does anybody know what causes it, I would love to know more about this phenomenon.





Thanks.|||You are simply stimulating your optic nerve, but instead of


using light, you are stimulating it with mechanical pressure on


your eyeball. You get that random dot pattern because the


pressure is transmitted through the fluid, spread over the


whole retina, and to the optic nerve. If it were possible to


transmit the pressure to one specific point, you would see


light just at that one point.