I'm Sarah Udal and this is my web page about optical illusions. This topic is particularly interesting to me as it integrates my main degree subject which is psychology with art, which having studied at A level is one of my interests. To start with here is one of my favourite illusions. One goal of our perceptual system is to keep the appearance of objects constant, even though their impressions on our retinas are continually changing. However our perceptual system does have some limitations and interpretations of the world are sometimes mistaken.
Optical illusions are a category of perceptual failures.
Illusions come about in part because the perceptual system is so active, constantly filling in gaps and providing interpretations that go beyond the information provided by the senses. To see many common optical illusions and their perceptual explanations click here . I was particularly pleased to find the web page written by Richard Gregory as he is among the honorary staff within the department of psychology. On the page there is a great example of an optical illusion which can be seen on the wall of a cafe at the bottom of St Michaels Hill here in Bristol. Even though the rows of tiles look like wedges they are actually parallel.