ALL ABOUT EYES
Ever wondered just how our eyes work or what does 20/20 actually mean?! Maybe it’s just us, but we think the eye is pretty amazing in all it actually does throughout our day to help us see. We’re going to break it all down for you so you can see just how cool our eyes really are! They are kind of like a camera in many ways, but we’ll get into that…
How does the eye work?
The eye is pretty complex, but a lot of it boils down to light and how that light is interpreted. It starts when light enters the eye through the front of the eye at the cornea. The iris, or colored part of the eye, can then dilate to let more light in or constrict to let in less light. Once the light or image hits the lens, it is flipped upside down. The lens works with the cornea to expand or contract if it is able to do so as a way of focusing the image on the retina. When the lens expands, it is looking at something further away. When the lens contracts, it is accommodating or using it’s muscles to look at something closer. As we age, usually around age 40 give or take a couple years, the lens gradually looses the ability to constrict and create a clear image when reading. This is why we all will need reading glasses!
Once the light passes through the lens to the retina, the retina’s rods and cones will convert the light into signals that the brain can interpret as images or colors. These signals travel along the optic nerve to the brain, where the brain flip the image right side up again and turn those signals into the images we can make sense of. The crazy thing is that this whole long process happens in a split second over and over all day long, so we never realize just how hard our eyes and brain have to work to help us to see! This video we found sums up this process perfectly, so if you’re more of a visual learner, this one is for you!
The Eye is like a camera
You may have heard this, but weren’t exactly sure what that meant. Much like the iris of our eyes, a camera has an aperture that allows more or less light into the camera. It also has a lens element and mirror that send the image to the viewing system like our eyes send signals to our brain! To compare your eye in terms of a camera though, the resolution of our eyes would be 576 megapixels! This is pretty incredible when you think that the iPhone 15 has a 24 megapixel camera and the iPhone 16 has a 48 megapixel camera. While technology continues to advance year over year, our eyes are still the absolute best camera! This is why a sunset or fireworks look so amazing in person, but just don’t look quite as detailed or fantastic on your iPhone!
What does 20/20 vision mean?
At your vision exam, you may be told that you have 20/20 vision or 20/25 vision or maybe without glasses the vision is 20/400. Well, that can be rather confusing! So for 20/25, that really means is that someone with perfect vision can stand 25 feet away from an object and see it clearly, but you need to stand 20 feet away, a little closer. So for 20/400 vision, you’d be standing at 20 feet, but those perfect eyeballs can spot it at 400 feet away! Pretty crazy, huh? Although our exam lanes are not 20 feet long, the screens the chart is displayed on are actually calibrated to account for 20 feet away to get those accurate measurements.
We hope this breakdown of the eyes, how they work, and how they are similar to a camera will help you realize just how wonderful our eyes are! Next time you go in for your eye exam, you’ll have a better idea of what that 20/20 vision means and mopre appreciation for our little eyeballs and all that they do!
