Optical illusions as metaphors

In the TOK book, we see that R.van de Lagemaat introduces optical illusions as metaphors to explain how we often perceive life poorly. For this blog assignment find an optical illusion on the net, post it on your blog, and explain how it acts as a metaphor on how we simply get things wrong.

Which circle is bigger, the one on the left or the one on the right?

At this point in life, I don't think someone can still be teased by questions like this one, because we all know about the existence of optical illusions and the tricks they play with our minds and our senses. Only if you're younger than a ten years old you can answer "the one on the left". Otherwise, you will probably know that the two circles have the same size, the one on the left only looks bigger because it's surrounded by little circles and, on the other hand, the one on the right looks smaller because it's surrounded by big circles.

Most perceptual illusions have to do with the sense of sight because, though it's one of the senses we most rely on, it's also the one who's most likely to be misled.

In the case of the optical illusion above, the image plays tricks on our sight and on our mind because of its context. In fact, the way we see something usually depend on the context in which we perceive it. We do often judge the size of an object by looking at its overall context. If there were no other circles surrounding the middle ones, we could have clearly seen that there are no differences in their size. 

This should teach of how sometimes is not advisable to rely on your senses, but i still think that they are the only way we can feel reality. Though I know I can't always trust one of them, the five of them together, along with the sixth, which is the ability of reasoning - my mind-, can often give me an accurate perception of reality.