Optical illusions like this one to find a hidden number exploit your visual processing system and brain's ability to make assumptions in the absence of complete information. But if you possess sharp ...

How good are you at noticing details that others often overlook? Take this optical illusion test and see if you can ace it under the time limit.

Optical illusions are older than you think. The first optical illusions date back to 20,000 BC and took the form of cave sculptings. Nowadays they are found all over the place – on screens, in books ...