5 Minute STEM Activity 18: Blind Spots - Make Yourself Disappear

To see as we do, our brain takes the information it receives from both eyes, puts it together and makes sense of it. Your eyes can't take in everything all at once non-stop, so our brain fills in any missing information. Sometimes it gets it a little bit wrong...

Make Yourself Disappear!
Find your blind spot

EQUIPMENT:
Yourself
Paper - scrap paper is fine
A pen or something to draw with
Optional - A photograph
Make your hand disappear.

Put your hand in front of your face between your eyes. If you close one eye and then the other, you can clearly see each side of your hand, but you cannot see both sides of your hand at once, in fact part or all of your hand will disappear. This blind spot is entirely to do with location, but your eyes also have a real blind spot.

The place where the optic nerve from the brain plugs into the back of your eye has no optic receptors. It cannot capture what the eye sees and it leaves us with a blind spot. You can find your blind spot with a simple trick...

Finding Your Blind Spot.

You need to have 2 things to focus on.

1. Draw a smiley face and an X on a piece of paper. They should be about 1-2cm tall.

2. Hold the paper at arm's length.

3. Close one of your eyes. If you can't wink then put your hand over your eye.

4. Focus on the image on the opposite side of the paper - so if you closed your left eye like my son, look at the smiley face with your right eye. If you closed your right eye, look at the X.

5. Bring the paper slowly towards you, still looking at that same image. The other image will vanish... As the paper carries on coming towards you, it will reappear.

6. Do the same, but use paper with a small, repeating pattern. Even lined paper will work. Your brain tries to fill in what it cannot see, which is why we don't notice our blind spot, and why we sometimes think we see things move in the corner of our eye.

What do you think will happen to the pattern when the smiley face disappears?

You can try doing the same with a photograph on a wall or shelf instead of a smiley face. If it's you then it's even better. You will have to walk towards and away from the photo to make it disappear. With a bit of practice, you can even make anything disappear... at least for a second.

You can find all of my 5 Minute STEM Activities here... None cost more than pennies or need anything you won't find in most homes. STEM learning can be fun for everyone...