Mission 1: How The Eye Works

Who is Professor Hallux?

Professor Hallux is a scientist who is really curious about everything to do with the human body!

With the help of Nurse Nanobot he wants to find out everything he can about how the human body works.

Watch this video where Professor Hallux and Nurse Nanobot find out how the human eye works…

After that you should have a good idea about what’s inside the eye and how it works.

Let’s run though the different parts of the eye and what they all do

Eyelids

These are the skin parts in front of the eye ball.

They keep the eye wet and clean by opening and closing – this is called blinking!

We can control blinking ourselves – which is great for a staring competition! But our body can also make our eyelids blink whenever they need to on their own without us thinking about it!

This ‘blinking on their own’ our eyes do is great because our eyes need to stay wet so we need to blink several ties a minute. Just think how annoying it would be if we had to think to blink and do it ourselves a few times every minute… it would be so annoying!

How does blinking make the eyes wet?

Well the the eyelids have little holes in them called ‘tear ducts’. These shoot out small amounts of liquid that help wash away any dirt in your eye and keep it nice and moist.

Tear ducts are also wear your tears come from when you cry.

Eyelashes

Your eyes are very delicate so you can’t have any dirt getting in there and causing any damage to them!

Eyelashes help act as a little barrier and help keep dirt out of your eye.

Sclera

This is where the words start getting harder to remeber!

This is the white part of your eye. If you think of the eye like a person then the sclera is the coat that it’s all wrapped up in.

Cornea

This is a transparent (see-through) dome that sits in front of the coloured bit.

The cornea helps the eye focus as light makes it way through the dome.

Iris

The iris is the coloured part of the eye.

It’s actually a ring of muscles that gets bigger and smaller to make sure that the right amount of light. gets into your eye.

If there’s lots of light, the muscle will tighten to make the hole smaller so that too much light doesn’t get int the eye.

If you’re trying to see in the dark then the muscle relaxes and the hole gets bigger so that it can get as much light as possible into the eye to help you see.

Pupil

This is the black dot in the middle of your eye.

It’s actually just a hole in your eye! It’s the hole in the middle of the iris that lets the light into the eye.

Lens

This is the part behind the iris and the pupil.

This part helps to focus the image you’re seeing as light passes through it. The lens gets thicker or thinner in order to focus the image onto the retina.

Retina

This is the part at the back of the eye where the image that we see gets carried to the brain.

Vitreous Body

This basically what the eye is filled with.

It’s a clear jelly like material and it’s very wobbly!

Your mission is to be a pirate!

You’ve found out a lot about how the eye’s works, now your mission is to put yours to the test.

Pirates used to wear eyepatches over one eye because it helped them see in the dark. The eye under the eye patch was always in the dark so the iris would open up to try and let more light in and that eye would be adjusted to see in the dark better.

This meant that when a pirate had to go down under the deck of the ship, where it was really dark, they would just have to uncover the eye under the eyepatch and it would already be well adjusted to see in the dark!

Give it a try! Make an eye patch (or just cover one eye with your hand) for five minutes in a brightly lit room. Then turn off all the lights and open your eyes! You’ll see that the eye that was covered can see really well and the one that was open before will need some time to adjust.