the sun goes down

Disclaimer: As you read this, you do not really see the pixels, the screen, your hands, and the surroundings, but an internal and three-dimensional image that reproduces them almost exactly and that is constructed by your brain. The photons emitted by your screen strike the retina of your eyes, which transform them into electrochemical information; the optic nerves relay this information to the visual cortex at the back of the head, where a cascade-like network of nerve cells separates the input into categories (form, color, movement, depth, etc.).