Thanks to our nervous system, sense organs and locomotor system, we are able to interact with our environment. Our sense organs detect information from the environment and our sensory neurons transmit this information to our brain.
Eyes, for example, are the sense organs for sight. The iris is like the diaphragm of a camera: it controls the amount of light that enters the eye. Cameras and eyes both have lenses that focus the light. Instead of film to record the image, our eyes have a retina. But there is an area where the optic nerve leaves the eye that is called a blind spot because it doesn’t respond to light.
In our Science project we found out if our eyes have a blind spot. We investigated using a scientific learning approach: question, hypothesis, method, conclusion.
1. Question: Do our eyes have a blind spot?
- I think that both eyes have a blind spot, or…
- I think that all parts of our eyes respond to light
We have to prepare a blind spot tester
We need a white card, a black felt-tip, a pencil, a long ruler and scissors.
First we have to cut a strip of card 25 by 5 centimetres.
Then we mark a small cross on the right side of the strip.
Then we measure 20 centimetres from the cross and mark a small dot on the left.
Then we hold the tester 50 centimetres from our face.
Then we close our left eye and look at the cross with our right eye.
Then we slowly bring the tester closer as we look at the cross
Finally we repeat but now closing our right eye and looking at the dot with our left eye.
- The dot disappears while looking at the cross when the strip is very close.
- And the cross disappears while looking at the dot when the strip is very close.
Both our eyes have a blind spot. Not all parts of our eyes respond to light. But when we use both eyes we don’t notice the blind spot.
We love Science!