You may vaguely recall Anatomy 101 as being boring. Perhaps at the age we took that class, we didn’t have had the appreciation for our health that we do now. Yet today, if we learn the basic anatomy of the eye, we can avoid unnecessary future trouble—something that interests everyone these days.
Imagine the eye as a camera that captures photos. “Photo” is a Greek word that means “light.” The parts of your eye work together to capture light and convert it into images that your brain can interpret. Let’s travel with a wave of light as it makes its way to your eye, and see what happens.
Cornea
First, the light wave reaches your cornea, which the National Eye Institute notes is a thin membrane that protects the eye and refracts (or “sends”) the light to its next destination. Since your cornea is not sustained with blood vessels and is completely transparent, your vision is unobstructed.
Lens
The cornea bends waves of light and sends them through the dynamic pupil to the crystalline lens of your eye. The lens works to focus the light waves. Imagine the videographical technique of out-of-focus and into-focus wavering. Your lens does the same job. When your children run toward you, the lens is what keeps your image of them from developing focal blur.
Retina
From the lens, the light waves travel through the vitreous body to the light-sensitive cells that make up the retina. The retina is the inner surface of the eye, and when the light moves through the eyeball, it reaches the retina on the back curve of the eye.
Rods and Cones
The retina contains millions of light-sensitive cells called rods and cones. According to the Mayo Clinic, cones are grouped toward the middle of the retina, in a zone called the macula. When light is abundant, like when you’re outside, the cones sharpen central vision and collect fine details. They also detect color hues, like the array of autumn leaves. Meanwhile, the rods gather information that, once sent to the brain, becomes what we know as peripheral vision. Consider these processes as you read this article. Without taking your eyes from the screen, can you see your coffee mug on the desk beside you? The window a few feet away? If so, your retinal cones and rods are to thank.
Optical Nerve
The light waves end their travels here, because the retina converts their frequencies into electrical impulses which are carried by the optical nerve to the brain, where they are interpreted. The product of a healthy eye is a clear, sharp, colorful, and complete image.
As Hannah More famously said, “It is not so important to know everything as to know the exact value of everything, to appreciate what we learn, and to arrange what we know.” You don’t need to be an eye surgeon to appreciate the job of the lens, for example, so you can—and should—cultivate an appreciation for the anatomy of the eye and the way your eyes work.
For questions or comments, contact Woodhams Eye Clinic.
Image source: Flickr
