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10 things you might not know about eyes

How much do you know about eyes? Photo: Shutterstock
How much do you know about eyes? Photo: Shutterstock

Did you know that after your brain, the human eye is one of the most complex organs in your body?

It’s their business but Optometry Australia, the peak professional body for optometrists, has shared some of the more weird and wonderful facts about your mince pies (also known as eyes).

The development of eyes – in a basic form in animals – goes back a whopping 550 million years.

Oh, and of course, you know the the most common eye colour in the world is brown.

Here are Optometry Australia’s Top Ten fascinating facts:

Fun fact No.1:

That's a wink - not a blink! Photo: Shutterstock
That's a wink - not a blink! Photo: Shutterstock

We blink around 10-15 times a minute and around 6.3 million times a year.

Fun fact No.2

No change from birth to death. Photo: Shutterstock
No change from birth to death. Photo: Shutterstock

Our eyeballs remain the same size from birth to death while our noses and ears will continue to grow.

Fun fact No. 3

The optic nerve. Photo: Shutterstock
The optic nerve. Photo: Shutterstock

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.

Fun fact No. 4

Muscling up. Photo: Shutterstock
Muscling up. Photo: Shutterstock

We might pump iron, compete in triathlons and climb mountains but the most active muscles in our body are those that control our eyes.

Fun fact No. 5

Every iris is different. Photo: Shutterstock
Every iris is different. Photo: Shutterstock

An iris has 256 unique characters – 6.4 times that of a fingerprint – which makes a retina scan ideal for security.

Fun fact No. 6

So little, but so many light-sensitive cells. Photo: Shutterstock
So little, but so many light-sensitive cells. Photo: Shutterstock

An average eyeball is 24 millimetres wide. It weighs only 28 grams yet it contains around 107 million light sensitive cells.

Fun fact No.7

Think of eyes as cameras. Photo: Shutterstock
Think of eyes as cameras. Photo: Shutterstock

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.

Fun fact No.8

Get set, flip. Photo: Shutterstock
Get set, flip. Photo: Shutterstock

Our retinas actually perceive the world upside down and it is our brain that flips the image the right way up for us.

Fun fact No.9

The colour collective. Photo: Shutterstock
The colour collective. Photo: Shutterstock

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.

Fun fact No.10

Eyelashes come to the fore when you sweat. Photo: Shutterstock
Eyelashes come to the fore when you sweat. Photo: Shutterstock

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.

And two more to boot ...

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).

Ryan Gosling eyes ... swoon.
Ryan Gosling eyes ... swoon.

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 precious organs, Optometry Australia recommends regular eye examnations. You can learn more here