the-eye

Okay, bad joke alert – but relevant to this week’s Science lesson nonetheless! 😉

On Wednesday in Science the ELP pupils investigated the workings of the eye. (Pun intended).

Earlier in the week we had enjoyed the wonders of the optical illusion – discovering that the eye can fool the brain into thinking it is seeing something removed from reality. Now we were going to look more closely at how this amazing part of the body works…

Here is our model eye.

We used this to help us investigate the inner structures that are more difficult to see than, say, the eye lashes or eyebrows. Look at the attached worksheet Mrs Allan made to help us discover more about the eye. Key terms that we were interested in learning included :-

• the eyelid
• the eyebrow
• the pupil
• the iris

Extension key terms we were interested in included

• the retina
• the lens
• the sclera
• the optical nerve

We learned in S1 about making a rainbow using a glass block called a prism. We loved the ROY G BIV song and it still helps us remember about bending light to make the colours of the spectrum. We needed to use this prior knowledge to help us work out what happens in the eye when we look at an object. In the eye the light is also bent – this time by a lens. We thought about how this works – and considered that one of our classmates had more than one pair of lenses. Can you think why?

We considered the pupil of the eye – and did a straw poll to decide what it is. A number of ideas were put forward…

• it is a black spot
• it is a dot
• it is a hole
• it is like the front of a camera

We decided to try a simple experiment to help us deduce what the pupil may be…

We paired up with a friend. One of us covered our eyes with our hands so that we could not see anything. We waited until our partner had counted to twenty before uncovering our eyes. Our partner stared into our eyes and watched what happened. Something special appeared before us…

Look at the picture on the right. It is a drawing of a “dilated eye”. This is how our eyes looked as soon as we took away our hands. The pupil was large and the iris was small. As our eyes adjusted to the light again the pupil began to get smaller…looking more like the drawing on the left of the diagram below.

We deduced that the pupil must be able to get bigger and smaller – and that it was more likely to be a hole rather than a dot or a spot. A hole that might let the light in…