• Anything less than five minutes to fall asleep at night means you are sleep deprived. The ideal is between 10 and 15 minutes.
• Seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol-level of 0.05%.
• Exposure to noise at night can suppress immune function even if the sleeper doesn’t wake. Unfamiliar noise, and noise during the first and last two hours of sleep, has the greatest disruptive effect on the sleep cycle.
• 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.
• Elephants sleep standing during non-REM sleep, but lie down for REM sleep.
• Scientists have not been able to explain a 1998 study showing a bright light shone on the backs of human knees can reset the brain's sleep-wake clock.
• The 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster and the Chernobyl nuclear accident have all been attributed to human errors in which sleep-deprivation played a role.
• Tiny luminous rays from a digital alarm clock can be enough to disrupt the sleep cycle even if you do not fully wake. The light turns off a “neural switch” in the brain, causing levels of a key sleep chemical to decline within minutes.
• Experts say one of the most alluring sleep distractions is the 24-hour accessibility of the internet.
• Most of what we know about sleep we've learned in the past 25 years.
• Teenagers need as much sleep as small children (about 10 hrs) while those over 65 need the least of all (about six hours). For the average adult aged 25-55, eight hours is considered optimal.
• Snoring occurs only in non-REM sleep.
• Ten per cent of snorers have sleep apnea, a disorder which causes sufferers to stop breathing up to 300 times a night and significantly increases the risk of suffering a heart attack or stroke.
• As a group, 18 to 24 year-olds deprived of sleep suffer more from impaired performance than older adults.
• A new baby typically results in 400-750 hours lost sleep for parents in the first year.
• The extra-hour of sleep received when clocks are put back at the start of daylight in Canada has been found to coincide with a fall in the number of road accidents.

-Source: ABC News Australia