If you want to have a go at creating your own illusion, take a look at our guide on how to download Photoshop so you have the tools to make your op art or check out our guide to the best monitors ...

This illustration, known as The General’s Family, is one of the most famous optical illusions of all time. Created by Mexican artist Octavio Ocampo, it contains a total of 9 hidden faces. Can you spot ...