Our eyes are amazing. They work around the clock to take in everything around us, even when we aren’t focusing on it. Even when you’re daydreaming during a boring class or staring out the window on a long car ride, your eyes continue to pick up images that get sent to the brain for processing. But while our eyes may be incredible tools that help us navigate our surroundings, we learn surprisingly little about them in school. That’s why we’re bringing you 15 eye facts that you may not know.
1. A Blink Lasts 1/10th of a Second
Blinks seem so fast that its hard to imagine measuring their speed. But, scientists have. Each blink actually lasts an average of 1/10th of a second. That may not seem like much. But when you consider just how many times a person blinks each day, you see just how much it adds up. The average person blinks between 15 and 20 times a minute, up to 1,200 times an hour, and up to 28,000 times a day. That’s a lot of blinking! Before you try blasting out 10 blinks in a single second, you should know that the max is actually 5 blinks per second.
2. Brown is the Most Common Eye Color
There are a lot of eye colors out there. Different shades and variations make every set of eyes a little different from the next. But we usually categorize eye shades as one of three colors, including blue, green, or brown. In reality, there are actually six shades that encompass all of the eye colors in the world. Besides the most common three, there is also amber, gray, and hazel. In a few rare cases, children and adults with albinism can also have eyes that appear to be red. This is actually because their irises have very little color, so the blood vessels show through, giving their eyes a pink or reddish hue. Because eye color is passed on through genetics, you might think that the colors are dispersed pretty evenly among the population. But that isn’t the case.
Brown is the most common eye color. That’s because brown eyes are a dominant gene, which means it gets passed down to the next generation far more often than the other eye colors. Other eye colors do obviously still get passed on, but at a lower rate than brown shades. One reason why the brown eye gene may be so dominant is that it was the eye color of the original humans to walk this planet. Blue eyes, on the other hand, are relatively new phenomena. Scientists think that the first blue-eyed individual didn’t walk among us until around 6,000 years ago.
If this is correct, that would mean that all blue-eyed individuals in the world today share a common ancestor who passed that trait on to them!
3. Staring at a Computer Can Tire Your Eyes
If you’ve ever noticed that your eyes feel heavy or overly dry after looking at a computer screen for too long, there’s a simple explanation. When you look at a computer, you actually blink less. In short spurts, you may not even notice this. But if you stay in front of the screen for long enough, your eyes will begin to dry out. This will leave them feeling heavy and tired.
Spending too much time looking at a computer screen can actually lead to vision problems. Computer Visions Syndrome can lead to blurred or double vision, dry, itchy red eyes, and even headaches or neck pain. If you’re able to, reducing the amount of time you spend in front of a computer screen is a simple way to reverse the effects of Computer Vision Syndrome. But if you work on a computer or otherwise can’t avoid it, there are other ways to combat the symptoms.
One way is called the 20-20-20 tactic. For every 20 minutes that you spend looking at a computer screen, you should spend 20 seconds focusing on something that is at least 20 feet away.
4. Most Vision Problems are Curable or Avoidable
When it comes to facts about eyes, this might just be the saddest. Around the world, 80% of all vision problems are avoidable, and many are even curable. Around the world, there are more than 2.2 billion people who need vision correction but don’t have access to health care services that could provide it. Many of those cases are connected to cataracts. Cataracts are treatable through a routine surgery. But despite this, there are more than 18 million people around the world suffering from blindness as a result of cataracts.
An additional 52 million suffer from moderate to severe vision loss as a result of untreated cataracts. More than 90% of those affected by blindness or vision loss due to cataracts are living in developing nations. Other common causes of blindness around the world that are less easy to treat are diabetes, glaucoma, and head injuries.
5. Shark Eyes May be Used for Human Surgeries
Because the optic nerve that connects the eye to the brain is so sensitive, scientists have yet to be able to transplant an eye. But they have developed other procedures to correct many common eye problems. Perhaps the most surprising solution that has been developed is the use of shark corneas. Because sharks’ corneas are so similar to humans’, scientists have used them for human corneal transplant surgery.
Similar corneas aren’t the only eye traits that humans and sharks share. The Hammerhead shark, with its wide head and eyes set far apart, have stereo vision similar to that of humans. That means that they have improved depth perception, making it easier to hunt their prey and navigate their surroundings.
6. Eyes Detect 36,000 Pieces of Info an Hour
Every single second that you’re awake, your eyes are working to process the world around you. From deciphering words to delivering important alerts to parts of your body, your eyes take in information constantly. In fact, every hour, your brain detects more than 36,000 pieces of information. If you’re awake for 16 hours a day, that’s more than 576,000 pieces of information!
Your eyes aren’t actually handling the processing though. While they do take in the information in the form of light, these images get passed along to the brain. It’s there that the light information gets turned into images that we can understand and process. Your eyes have to be incredibly strong to keep up with this level of work. Luckily, they have more than 7 million cones and 100 million rods that take in light and help to send images to the brain for processing.
Want to keep your eyes working this hard? Regular eye exams are a must!
7. Scientists Don’t Know Why We Cry When Upset
Our bodies produce tears in order to clean the surface of our eyes. That’s why dusty areas can make your eyes water. But what scientists don’t know is why we cry when we’re upset, excited, or angry. They have yet to find a biological link between crying and emotions that would explain the phenomena. This also means that scientists aren’t sure why some people are more prone to crying in certain situations than others. One thing they do know is that we aren’t born with tears. Babies cry right from the start. But that crying won’t produce tears until they are between 1 and 3 months of age.
On the flip side, we actually produce fewer tears as we age.
8. There’s a Perfect Amount of Eye Contact
If you’ve ever worried about whether you’re looking at a person for too long when you first meet, you’re in luck. There is actually a science-backed length of time that you should make eye contact when meeting someone new. When you’re meeting someone new, look into their eyes long enough to notice their color. This should take just under 4 seconds. Studies have shown that this amount of time is just enough to establish a connection without making the other person uncomfortable.
9. An Iris Has More than 256 Unique Characteristics
You likely already know that your fingerprints are incredibly unique. But did you know that your irises are even more so?
Your iris has more than 256 unique characteristics. As a result, eye scanning systems are some of the best security features available today.
10. You Only See 1/6th of Your Eye
All of the facts about eyes on this list are interesting. But this might be the most surprising. While each persons’ eyes may seem like they are a slightly different size, all eyes are around an inch across and weigh about 0.25 ounces. If that seems pretty large, that’s because you only see around 1/6th of your eye.
11. The Eye Has Blind Spots
Where your optic nerve connects to your retina, your eyes actually have a blind spot. This would cause a hole in your vision. But if you’re thinking you’ve never noticed a blind spot before, that’s because you haven’t. Each eye works to fill in the gap in the vision of the other eye, so it goes completely unnoticed by us. While your eyes work perfectly together to fill in these holes in our vision, believe it or not, one of your eyes is at least slightly stronger than the other.
12. Blue or Green Eyes Can Be a Recessive Gene
You already know that brown is the most common eye color and that brown eyes are caused by a dominant gene. While blue or green eyes may not be dominant, and therefore don’t occur as often, they can be recessive. This means that even though a child is born to parents with brown eyes and he or she also has brown eyes, they may still carry the blue or green eye gene. As a result, their children or grandchildren may end up with green or blue eyes.
13. Eyes are Our Second Most Complex Organ
After reading the other interesting facts about the human eye on this list, this one should come as no surprise. After our brains, our eyes are the most complex organ in our bodies. Working 24/7, and packed full of tools that aid our vision and perception, they truly are amazing. This is more than another one of the fun facts about eyes you didn’t learn in school. It should also be a reminder that protecting these important organs is a must.
14. Eyes Never “Turn Off”
When you wake up in the morning, it takes a few seconds for your brain to realize that you’re awake. Before you go for a long run, you might need to stretch or do a little jogging to get your leg muscles firing. Babies have to learn how to crawl and then how to balance before they can walk.
But your eyes never need to be “woken up” or trained to work. They know exactly what to do, and are ready to do it 24/7. In fact, your eyes continue to work even while you sleep. While they stop sending images to your brain, they do continue seeing light. That’s why bright sunlight through your window can wake you up.
15. Humans See More than 24 Million Images in a Lifetime
The average human will live to 81 years of age if they are female, or 76 years of age if they are male. If you live to the average age, your eyes will have processed more than 24 million images throughout your lifetime.
Now That You Know a Few Interesting Facts About Eyes, It’s Time to Protect Yours
Now that you’ve learned a few of the eye facts that nobody taught you in school, let these facts inspire you to start taking better care of your own eyes. Regular eye exams can help you learn about potential problems before they become serious, making it easier to treat them. If you begin experiencing minor eye issues or have a more serious injury, it’s very important to get to an eye doctor right away. Leaving a condition untreated will only make it worse, and it may prevent proper healing even after treatment is sought.
If you’re ready to start protecting your eye health, contact us today to schedule an appointment.