Reading on iPad before bed can affect sleep habits
Apple's iPad can do movies, music, e-mail, apps and rich Web browsing. And of course, e-books. Should Amazon just put its comparably basic e-reader, the Kindle, to sleep?
Not so fast. Sleep experts say using the iPad before bed can affect sleeping habits unlike most other e-readers.
The difference? Devices like the Kindle, the Nook (the top part of the screen that displays books) and popular e-readers from Sony use a technology called e-paper. It simulates the look of an actual printed page and does not emit light. That means, unlike the iPad, you can effectively read in direct sunlight. (Beach, anyone?)
The iPad, however, contains a touchscreen liquid-crystal display that, like computer screens and television sets, emits light. On the plus side, you can sneak the device under the covers while your significant other sleeps beside you and flip through a couple pages of a book without a flashlight.
But staring at the screen before bed could leave you lying awake. That's because direct exposure to such abnormal light sources inhibits the body's secretion of melatonin, say several sleep experts.
If you've watched any late-night TV, you've no doubt heard the term thrown around in commercials for sleeping pills. Melatonin signals are sent through the brain as a response to darkness, telling the body to prepare to shut down for the night.
Light-emitting devices, including cellphones and yep, the iPad, tell the brain to stay alert. Because users hold those devices so close to their face, staring directly into the light, the effect is amplified compared with, say, a TV across the room or a bedside lamp, said Frisca Yan-Go, director of the UCLA Sleep Disorders Center in Santa Monica.
Some say e-ink is easier on the eyes than the screen on a computer (tablet or otherwise). However, the Wall Street Journal published a report this month to the contrary.
Yan-Go was eager to point out the advantages of books over e-readers. Paper books are often lighter; they can be dropped when you doze off holding them; and if they get wet, it's not the end of the world. And they won't mess with your sleep cycle.
"The take-home lesson is that insomnia and electronics gadgets emitting light should not [be] mixed before bedtime," UCLA Neurology Clinic Director Alon Avidan, also an associate professor at the university, wrote in an e-mail. However, "Kindle is better for your sleep," he wrote in another e-mail.
-- Mark Milian
Photo credit: Jay L. Clendenin / Los Angeles Times