What causes the odd shapes I can see when I apply pressure to my eyeballs?
When I close my eyes and press down on my eyelids, I see hundreds of what look like interlocking squares and assorted polygons, along with various colors swirling around. I guess the colors are just my optic nervous system being interrupted, but why the weird looking shapes?
If you press on your eyeballs like that, you can end up sort of moving/pushing on your optic nerve or mechanically triggering the cells in your retina. Nerves tend to malfunction when you squish them, so what you see is just how your brain happens to interpret the scrambled signals it receives (it’s essentially trying to process "brain static" that doesn’t really mean anything). It’s kind of like what happens when your arm or leg "falls asleep" after you’ve been sitting on it the wrong way; the disrupted nerve sends some scrambled signals, which gets interpreted as the tingling, pins-and-needles type feeling, except it’s with visual signals instead of touch or pain signals.