Your eyes are possibly the most important part of your body responsible for a large amount of your brainpower, and most of your perceptive ability. But hidden within your eyes are many secrets that you probably didn’t know about let’s take a look at 5 fun facts about eyes that you may never have realized, from a proper optometry blog.
1. Newborn Babies Are Born Colorblind And Don’t Produce Tears
That’s right! Newborn babies are completely colorblind their ability to perceive and recognize color develops over time outside of the womb, generally taking about 5 months to reach the same capacity as a fully grown adult. This development also corresponds with the ability of babies to track rapidly moving objects and focus at longer distances, and the development of depth perception.
In addition, newborns don’t have the capacity to create tears though newborn babies certainly cry quite a lot, the ability to “lacrimate” or create tears takes 4-13 weeks to fully develop in newborns this is due to underdeveloped lacrimal glands, which initially produce only enough tears to lubricate the eyeball and keep it drying out. After a time, these glands continue to develop, and enough tears accumulate that crying becomes possible for newborns.
2. Nearly A Third Of Your Brain Is Dedicated To Sight And Interpretation of Sight
The eye is an extremely complex organism, so it’s no surprise that our brains dedicate quite a bit of processing power to the interpretation of vision over 30%, compared to 8% for the sense of touch, and a measly 3% for smell.
For another comparison, the auditory nerves of the ear consist of approximately 30,000 bundled fibers, which allow sounds to be interpreted by the brain. Each of the optic nerves contains over a million nerve fibers a huge difference.
However, given the massive amount of information recorded by the eye color, shape, motion, depth perception, focusing and refocusing, interpretation of objects in front of others, and so on it makes sense that we dedicate this much brainspace to our eyes, especially because they’re our vision (especially color vision) are highly developed, compared to our other senses.
3. At Night, Your Cones Stop Working And Your Rods Take Over
The human eye has two main photoreceptors that allow it to interpret images. Cones are high-complexity, advanced photoreceptors that allow for the perception and interpretation of colors, but are much less sensitive in low light, whereas rods are extremely sensitive to light so much so that they can be triggered by even a single photon but lack color perception and other advanced sensitivity.
Because of this, at night, your cones mostly stop functioning altogether and your rods take over, leading to a process called scotopic vision wherein the highly sensitive rods take in maximum amounts of light, and allow you to see at the loss of some color perception. This is why, in low-light conditions, everything appears to be in shades of gray you functionally become colorblind.
This is also the reason that sudden blasts of light after being acclimated to night vision are so shocking and blinding the cones, formerly nonfunctional or deactivated by the lack of photons, jump back into life, leading to a bright flash and sudden jolt of activity.
4. Your Eyes Have A Blind Spot But You’ve Probably Never Noticed It
Each and every human being has a blind spot in their vision. This usually goes unnoticed, as the brain is generally able to process the image around it and fill in the missing image with other information.
This blind spot is due to the construction of the eye in all animals but octopus, nerve fibers are routed before the retina, leading to a small spot where perception is totally blocked, and disrupting vision, due to the nerves having no photoreceptors.
Interestingly, the octopus eye (and only the octopus eye) avoids this, by having nerve fibers route behind the retina, and the octopus has no blind spots because of this.
If you don’t believe us, check it out for yourself with this simple test. Open the link and follow the instructions to find your blind spot quite shocking, indeed though it doesn’t affect day-to-day-life for most of us.
5. Your Eyes Receive All Images Upside Down And Your Brain Flips Them
That’s right the actual nerves in your eye perceive images flipped 180 degrees completely upside down. The process of refraction that creates the image within your eye reverses the image when you receive it, and that’s how it hits the optic nerve.
However you don’t see anything upside down, and that’s thanks to your brain’s interpretation of the images you see. Along with determining color, speed, depth, and many other factors, your brain helps interpret what you see by flipping it to be the “correct” orientation.
To prove this hypothesis in the 1890, a man named George Stratton created a pair of “prism goggles” that flipped his vision mechanically, and wore them for over 8 days. Everything he saw was flipped for the first four, but then something amazing happened his brain reacted to this interpretation of his vision by flipping his vision again meaning he saw everything normally through the inverted glasses.
Truly, this is a testament to the durability, versatility, and power of the human eye and brain.
The eye is truly a miraculous sensory organ, and one of the most important to the human species, so it’s no surprise that it hides so many fun and interesting secrets.
And this is just the beginning scientists are still studying the human eye, seeking to unlock its perceptive and neurological secrets, so we can expect to learn even more about our eyes in the future.