The eye is a fascinating and powerful optical instrument. The eye can detect colors, focus automatically and adjust rapidly to the brightness of the surrounding light. It is only just recently that the most modern cameras have started to approach this level of sophistication. However, the eye and the brain still can do something that modern technology cannot do and that is automatically recogonize its image - even when part of it is not there or not seen clearly. This pattern recognition feature of the brain can be tricked by what our eyes see. When this happens we call it an opitcal illusion. The black and while optical illusions below rely on your brain trying to make sense out of what you see, even when it shouldn't.
There are also many color based optical illusions, which are due to the eye/brain's system to retain what it sees for just a short period of time. I will try to create some of those and put them on this page in the coming months.
For the illusions below you may have to get our your ruler to really tell what is going on and remember your brain often tries too hard to recognize what you are seeing.
Click on the pictures to see a bigger version of the picture (or draw your own).
We are always looking for more experiments - if you have some you would like to share you may send them to us and we will post them on the Web.