In 1965, 17-year-old high school student, Randy Gardner stayed awake for 264 hours.
That's 11 days to see how he'd cope without sleep.
On the second day, his eyes stopped focusing.
Next, he lost the ability to identify objects by touch.
By day three, Gardner was moody and uncoordinated.
At the end of the experiment, he was struggling to concentrate, had trouble with short-term memory, became paranoid, and started hallucinating.
Although Gardner recovered without long-term psychological or physical damage, for others, losing shuteye can result in hormonal imbalance, illness, and, in extreme cases, death.
We're only beginning to understand why we sleep to begin with, but we do know it's essential.
Adults need seven to eight hours of sleep a night, and adolescents need about ten.
We grow sleepy due to signals from our body telling our brain we are tired, and signals from the environment telling us it's dark outside.
