Too Much Light, Too Little Sleep?
Mar. 09, 2011 - Many Americans aren't getting enough sleep - and some experts blame late-night TV, text-messaging, and computer use for the problem.
The National Sleep Foundation's latest poll, released this week, surveyed 1,508 people ages 13 to 64 about their sleep. The results: 63 percent said they weren't getting enough shuteye.
The overwhelming majority - 95 percent - said they used a computer or cell phone or watched TV within an hour before bedtime several times a week.
It could be that the light emitted by those electronic devices is making it harder to fall asleep when they are finally turned off.
"Falling asleep isn't like flicking a switch," says Allison G. Harvey, Ph.D., at the University of California-Berkeley. "We don't put our heads on the pillow and fall off to sleep. We take time to wind down at night. If we've got bright light conditions, we're not giving ourselves a chance to get off to sleep and stay asleep."
Light exposure before sleep may disrupt body rhythms and suppress the release of the hormone melatonin, which promotes sleep, Harvey says. She adds, however, that this hasn't been proved with scientific studies.
Not all kinds of light activate body cycles in the same way, though. And people vary in their sensitivity to light.
"I have on rare occasions had patients who were 'light-toxic,' in that, if they got bright light late at night they couldn't sleep at all," says Matt Travis Bianchi, M.D., at Harvard Medical School. "Contrast that with patients I have who sleep with the light and TV on routinely, and don't have much problems that they can feel."
If you are one of those with a sleep deficit, what can you do?
Harvey recommends an electronic curfew - an hour before bed, dim the lights and click the "off" switch on your devices. Also, she says, "try to stick to a fairly regular wake time, get bright light in the morning and dim light at night, exercise regularly and have a bedtime routine of 30 to 60 minutes when you're letting yourself wind down."
Are You Getting Enough Sleep?
To determine if you're getting enough rest, answer the following questions:
- Do you have trouble falling asleep, staying asleep, waking up on time, or feeling refreshed after sleeping?
- Do you have at least one of the following problems?
- Low energy
- Attention, concentration, or memory problems
- Poor work performance
- Daytime sleepiness
- Making errors at work or while driving
- Frustration or worry about your sleep
If you answered yes to several of these questions, it's likely you're not getting enough sleep. Although sleep needs vary from person to person, generally, most healthy adults need seven to nine hours of sleep a night.
Always talk with your health care provider to find out more information.