Sight is a pre-installed biological system that processes light entering through two forward-facing apertures in the face (eyes). It is the dominant sense in humans, responsible for approximately 80% of all information received from the surrounding world. It operates continuously while the eyes are open, without requiring consent from the user.
This document is not primarily concerned with the mechanics of vision — the retina, the optic nerve, the brain's processing of colour and movement. This document is concerned with what seeing does to you: specifically, the documented role of visual experience in forming, maintaining, and confirming a sense of who you are. This role was, for the entire duration of recorded human history, considered so obvious that it was rarely discussed. It now requires a dedicated entry.