Vision or the ability to detect light and interpret it as sight rests on the eyes and its complex system. The function of the eyeball and all its components allows us to use our sense of sight in everyday activities which makes it a vital organ in the human body. But did you ever wonder how the eye works? The simplest way to explain how the intricate functions of each part work is to compare the human eyeball with a camera, as they both capture images and relay them in some form for people to interpret.
Light from the outside first hits the “cornea”, a clear dome-shaped surface that covers the front of the eyes. The cornea is built in such a way that it is able to refract (bend) light that passes through it. Once the light has been bent, it goes straight to the “iris” (that part of the eye that gives it its color) where the pupil is located and it is through this hole in the iris that light passes. The iris muscles enlarge and shrink the pupil much like the shutter of the camera depending on how much light needs to pass through. From the iris, light travels and strikes the “crystalline lens” which is responsible for focusing the light rays properly. Once through the lens, the light rays pass through the vitreous humor (a gel-like substance that holds the spherical shape of the eye) on its way to its goal, the retina.
The retina serves as the “film” of the eye if you continue with the camera analogy. It is responsible for catching and capturing the light rays, processes them and turns them into nerve impulses which then get carried out and sent through the optic nerve. The optic nerve is thus connected to the brain which interprets all these signals as images.
The set up looks extremely complex when you think about all the stops that the light has to go through to be converted as vision. It certainly makes you think how incredibly sophisticated the optic system is and hopefully makes you appreciate your eyes more.