Take a look at looking
Your sense of vision is arguably the most complicated sense you have. Estimates range from one half, to as much as two thirds of your brain dedicated to using light to make sense of your world. From the way your eyes turn light into nerve impulses, to different bits of the brain that process them, we take a close look at looking.
Here’s some links to more information about your retina. Located at the back of your eye, this structure turns light into nerve signals.
Here’s more information about the superior colliculus, an area of your brain that helps you move your eyes how you need to so you can see what you see.
Here’s more info on the lateral geniculate nucleus.
Here’s stuff about your primary visual cortex, nicknamed v1.
Here’s an article about a study done on the differences within your brain between real and imagined visual images.