When you're bored, when you want to wake your brain up, when you want to see something fascinating, try a spoonful of optical illusion. These puzzling images are guaranteed to completely draw your mind. Philosophically, they also prove the point that there are many ways of looking at one thing.

1. The 'Corner House Illusion' by Istvan Oroz illustrates the eternal concave-convex paradox. If you cover the top of the image with your palm, it looks like it's projected outwards. But once you look at the entire photo, you don't know anymore.

2. Are they standing? Are they lying flat? This dice illusion is just impossible!