Expanding hole illusion (IMAGE) Frontiers Caption The 'expanding hole' is an illusion new to science, strong enough to prompt the human eye pupils to dilate in anticipation of entering a dark space. Credit Laeng, Nabil, and Kitaoka Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.