Andrew Ilyas and Nikhil Patil - Optical Illusions - Does Colour affect the illusion ?

3 The attributes of an optical illusion Optical illusions are meant to fool the mind. However, the way in which they do this differs with every illusion. Illusions can be classified based on their two main attributes of colour and geometry. One may think that the more attributes an illusion has, the better, but using all the attributes would upset the balance, making the illusion to confusing. We will study only the colour attribute. 3.1 Illusions depending on colour The first attribute for an optical illusion is contrast. The theory behind this is that a colour appears to be different when in juxtaposition with two different colours. The type of contrast to be presented here is simultaneous contrast. Simultaneous contrast is used in after-images. In general, when being exposed to a colour for a while, and then looking at a white surface, it will look like the original colour’s complimentary colour. Some illusion artists use contrast on top of other attributes, so that they leave you confused even after looking at the illusion. (Luckiesh, 1992) The next colour attribute for an optical illusion that is presented here is sensor tiring, also known as growth and decay of sensation. An example of this is the spinning disc illusion. In this