Trouble sleeping? Maybe it's your iPad

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.