New research from Rensselaer Polytechnic Institute shows two hours of screen use will interfere with the normal nighttime release of melatonin. Melatonin is a key hormone in the body’s internal clock, or circadian system, which tells us when it is night. It also helps to make us sleepy.
If you interfere with that signal, then you can delay sleep. The Institute’s researchers showed two hours of iPad use at normal brightness before bedtime was enough to make that happen.
They also point out that the dose of light is important. Brightness, exposure time and wavelength determine how much melatonin is affected. Light in the blue and white range, like the light found in our computer screens, tablets and e-readers, is enough to do the trick.
In the future, manufacturers may get creative and make more “circadian-friendly” devices. But until that happens, here are a few ideas that may be useful:
- If your tablet or e-reader has a nighttime mode or a way to switch to white text on a black screen, use it.
- Turn down the brightness of your computer, laptop or tablet screen in the last hour before bedtime.
- Read the old fashioned way — get a book!