Lights

CNN) -- J.D. Moyer decided recently to conduct a little experiment with artificial light and his sleep cycle.
The sleep-deprived Oakland, California, resident had read that strong light -- whether it's beaming down from the sun or up from the screens of personal electronics -- can reset a person's internal sleep clock.
So, for one month, whenever the sun set, he turned off all the gadgets and lights in his house -- from the bulb hidden in his refrigerator to his laptop computer.

It worked. Instead of falling asleep at midnight, Moyer's head was hitting the pillow as early as 9 p.m. He felt so well-rested during the test, he said, that friends remarked on his unexpected morning perkiness.
"I had the experience, a number of times, just feeling kind of unreasonably happy for no reason. And it was the sleep," he said. "Sure, you can get by with six or seven hours, but sleeping eight or nine hours -- it's a different state of mind."