The record for the longest period without sleep is 18 days, 21 hours, 40 minutes during a rocking chair marathon. The record holder reported hallucinations, paranoia, blurred vision, slurred speech and memory and concentration lapses. It's impossible to tell if someone is really awake without close medical supervision. People can take cat naps with their eyes open without even being aware of it. On an average, humans sleep around three hours less than other primates such as chimps, rhesus monkeys and baboons, all of whom sleep for 10 hours.
