Optometry Australia, the peak professional body for optometrists, reveals that there are hundreds of interesting facts about the human eye – everything from their development in a basic form in animals some 550 million years ago, to the fact that the most common eye colour in the world is brown.
Here are Optometry Australia's Top Ten fascinating facts:
We blink around 10-15 times a minute and around 6.3 million times a year.
Our eyeballs remain the same size from birth to death while our noses and ears will continue to grow.
An eye is composed of more than two million working parts including over one million nerve fibres which connect each eye to the brain.
As a result of this maze of nerve fibres, an eye cannot be transplanted as it is currently not possible to reconstruct these connections.
We might pump iron, compete in triathlons and climb mountains but the most active muscles in our body are those that control our eyes.
An iris has 256 unique characters – 6.4 times that of a fingerprint – which makes a retina scan ideal for security.
An average eyeball is 24 millimetres wide. It weighs only 28 grams yet it contains around 107 million light sensitive cells.
The real machine behind our sight is our brain. Our eyes are mere cameras that capture light and they send this data back to the brain to be interpreted into shapes, colours and images.
Our retinas actually perceive the world upside down and it is our brain that flips the image the right way up for us.
You've heard of 50 Shades of Grey, well the human eye can see 500 shades of grey. And red, blue and green which are the only colours we can see – all other colours are a combination of these.
Our eyelashes play an important function in keeping dirt out of our eyes while our eyebrows are there to prevent sweat dripping into our eyes.
If you have blue eyes you will share a common ancestor with every other blue-eyed person in the world (Brad Pitt, Jennifer Lawrence or Ryan Gosling, for instance).
Your eyes don't show signs of many eye diseases – such as glaucoma and macular degeneration – until it is too late and their effects cannot be reversed leading to serous visual impairment and often blindness.
To protect these incredibly precious organs, Optometry Australia recommends regular eye examinations throughout life. To find an optometrist near you and to learn more about your eyes go to goodvisionforlife.com.au