How Eyes are like Cameras
Besides being the most painfully overused topic of close-up pictures on Instagram, the eye is a remarkable organ that controls one of our most powerful senses. Without it, you probably wouldn’t be reading this article in the first place - and what a shame that would be. Despite their ubiquity, most people have no idea how the eye actually works.
In many ways, eyes operate in a manner very similar to a camera. You would do well to think of the eye as a camera with a cornea. The cornea takes the broadly diverging rays of light and bends them through the pupil so that we can see them. The cornea is the eye’s primary focusing element, much like the focus on a camera.
The iris is the colorful part that all of those wistful teenagers are taking pictures of for their Instagram in the first place, and the pupil is the dark, round circle in the center of the eye. The iris and pupil, together, act like the aperture of a camera. The aperture, effectively, is the hole through which the light travels.
Next up for a hopeful beam of light traveling through the eye is the lens, which acts exactly like, y’all guess it - the lens of a camera! They both focus light, the anatomical one does so to the back of the eye. Once we reach the back of the eye, we finally get to the retina - sort of like the film in a camera. The retina is a membrane lined with photoreceptor nerve cells (the cones and rods) in the back of the eye.
These photoreceptors react with the light rays and produce electrical impulses that are sent through the optic nerve to the brain, and voilà - an image is perceived. Much like how the image is transmitted to the film, the chemical signals are interpreted as an image in the brain.
While this is by no means a conclusive description of the eye’s anatomy, I thought it was a pretty solid overview.
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