There's a reason why Facebook users spend hours on the social media site. According to a recent study on internet addiction from the School of Psychology and Neuroscience at the U.K.-based University of Kent, online and Facebook-related images can actually alter a person's perception of time. "We found evidence that Internet and Facebook-related stimuli can distort time perception due to attention and arousal-related mechanisms," the study said. "This highlights that Facebook-related stimuli lead to an overestimation oftime compared to Internet related stimuli, and both Facebook and Internet related stimuli were associated with better discriminability of time compared to matched neutral stimuli." In non-science speak - users lose the ability to keep track of time when they're scrolling through their Facebook news feeds. They plan to spend just a few minutes catching up on friends, but two hours pass before they realize it. Postgraduate researcher Lazaros Gonidis and Dr. Dinkar Sharma found that any type of internet usage could distort time perception, but Facebook usage was worse. The scientists observed the responses of 44 subjects who were shown 20 images for different amounts of time. Five pictures were Facebook-related, five contained generic online content and ten neutral photos were used as the experiment's control. The result? Participants underestimated the time spent looking at Facebook-related content more than other online images, but still underestimated the time looking at both types of photos. There are currently more than 1.86 billion Facebook users in the world. The average user spends 50 minutes a day on the site, which adds up to 304 hours, or 12.67 days per year.