You might want to grab on to the edge of your desk before looking at the image above. If you're like most people, the black oval will appear to expand, as if you're falling into a hole. At least that's what 86% of the people who took part in a new study – "The Eye Pupil Adjusts to Illusorily Expanding Holes" by Laeng, Nabil, and Kitaoka, published by Frontiers in Human Neuroscience — thought after this illusion tricked their pupils into actually dilating. — Read the rest