13 Fascinating Facts About the Human Eye | ExpatWoman.com

13 Fascinating Facts About the Human Eye

Did you know that your eyes are astonishing things? Here's 13 of our favourite mind-blowing eye facts you probably didn't know.

Posted on

30 January 2017

Last updated on 21 May 2017
13 Fascinating Facts About the Human Eye

You have to give it to them, eyes have come a long way since their first development over 550 million years ago. From the first eyes in single-celled animals to the human eye as we understand it today, our peepers are really quite fascinating. 

13 Fascinating Facts About the Human Eye


As they're made up of over 2 million working parts, it's no wonder they can achieve mind-boggling things that are truly fascinating to learn and understand. 

1. Your retina (the layer at the back of your eyeball that is sensitive to light) actually sees the outside world as upside-down.
It's your brain that flips the image for you. 

2. Eyes can heal very quickly... A corneal scratch only needs up to 48 hours to repair...
... with proper care, of course. 

SEE ALSO: 5 simple eye care tips for computer users

3. The human eye can distinguish up to 10 million different colours. 

4. All blue-eyed people can be traced back to one ancestor, who lived near the Black Sea over 6,000 years ago. 
In fact, having blue eyes is a mutation.

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5. If you have brown eyes, you're an original. All humans had brown eyes to begin with...
...until the blue eyes mutation appeared. 

6. Yes, you can sunburn your eyes.
This is called photokeratitis, and it burns the cornea and whites of your eyes. We advise not putting sun tan lotion in your eyes, though. 

7. If you were born with sight, but now blind, you will still see images in your dreams.

8. The average person blinks around 17 times a minute.
Admit it, you're trying not to blink now. 

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9. You cannot transplant an entire eyeball.
It's impossible to attach the optic nerve to the eye, it's too sensitive to reconstruct it successfully. You can, however, transplant our cornea. 

10. Newborn babys don't produce tears...
... they only start producing tears between 4 - 13 weeks old.

SEE ALSO: How air conditioning can ruin your eyesight

11. People born with two different coloured eyes have something called heterochromia.
The celebrity Jane Seymour has one brown eye, and one green eye. And actor Henry Cavill has an eye that's both blue and brown. 

12. Your corneas are the only tissue that doesn't have blood.

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13. Your tears have different compositions based on what mood you're in.
If something's irritating your eye, or if you're crying, yawning or happy.