Optical illusions are fun to look at, but the traditional variety can leave you with a major headache. Luckily, optical illusion photography is even cooler – but won’t have you going cross-eyed. These amazing black and white photos all play with the idea of reality and illusion, and they’re executed extraordinarily well. They’re from many different decades and have many different subjects, but the not-so-subtle trickery of all of them will definitely put a smile on your face. #11 is beautiful *and* impressive.