Student Zone

Optical Illusions

Your eyes are basically like television cameras. They simply collect the light you see and pass it to your brain in a way that your brain can make sense of it. The problem is that your brain makes some assumptions about what it sees. In other words it takes a guess at some parts of what you see. Certain types on image can "fool" your brain into thinking something is happening when it isn't.

Dots that are white while looking at them, black when you're not!

Mystical Wheel - is it moving? Trace your eyes around the rim.

Are these lines parallel? Measure them

Find Your Blind Spot!

Open the image by clicking on the thumbnail in the left column. There is a dot and a cross. You can print this out or just do it on the screen. Cover your left eye and move yourself away from your screen or printout so that you are looking directly at the dot from some distance away. Keep looking directly at the dot and move towards it. As you do so, the cross will move away from you in the corner of your eye. At some point the cross will disappear! As you keep moving in, it will re-appear and continue moving out. If you move back and forth, you will see the cross appear and disappear. This will demonstrate the edges of your blind spot. Just to check, cover your right eye and do the same - no blind spot! That's because your left eye's blind spot is to the left of the dot. You can check this one as well by turning the printout upside down if you've printed the image.

Why Does it work?

Your brain is connected to the back of both of your eyes by your Optic Nerve. Where the nerve connects to your eyeball, there is a patch that cannot detect images. The blind spot isn't at the sides of your vision but quite close to the centre. So why can you see everywhere and not see a "hole" in your vision? There are two reasons. Firstly, you have two eyes, so one fills in the gap from the other's blind spot. The problem is, if you cover one eye, you can still see everywhere - or so you think! Your brain seems to cover the hole so that it is not obvious when you look. Your brain seems to blur the surrounding area together so that you think the area inside the blind spot looks the same as everywhere around it.

It is this that actually allows you to see the blind spot. If you look at a small image that will fit completely inside your blind spot, your brain will "erase" it from your vision by blurring the surrounding area.

Grid Game

Test your concentration skills by finding and following the number sequence before the timer runs out. Every game starts with a random number, you need to find that number, then the next number in the sequence.

Did You Know:

1.	Your brain weighs about one third of a kilogram when born and eventually could weight as much as 1.7 kilograms
2.	For doctors in Australia to declare that you are legally dead, they need to check for electrical activity in your brain stem. If there isn't any - that's it - your dead! Mind you. if there wasn't any electrical activity in your brain stem, you wouldn't know about it anyway!
3.	Scientists in the 1970's and then 1980's believed that technology was developing so fast that we could build an artificial brain by the turn of the last century. What they didn't realise is that brain research has been showing that the human brain is so much more complicated than a computer that scientists are now saying that may not be possible for another twenty years!
4.	When you sleep, your brain doesn't slow down like the rest of your body. In fact, at some stages during the night, your brain actually works harder than it does during the day.
5.	A dolphin's brain is much bigger and more complicated than a human brain. Does it make them smarter than us? Scientists think not. In fact brain size doesn't have a lot to do with how smart you are. Albert Einstein's brain was apparently below average in size for a human being.
6.	Research is being done to enable devices such as cameras and calculators to be "plugged in" to the human brain. This could allow blind people to see or let humans "see" radio waves and heat signatures. Imagine being able to see in the dark!
7.	To cure severe epilepsy in really young people, doctors can remove one half of the brain ( a "hemispherectomy"). This cures the problem and most people go on to lead a perfectly normal life!
8.	Drugs that effect your brain like alcohol tend to last for short periods of time in your brain. Some illegal drugs like marajuana can still be affecting your brain months after you ingest a single dose! Some drugs such as L.S.D. can severely and permanently damage your brain after only a very short period of sustained use.

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