Narrator: It's 1:00 a.m. You should be sleeping but you're glued to your smartphone, catching up on the latest news, Facebook updates and tweets. It turns out that the smartphones and tablets that keep you connected and organized may also be keeping you awake.
[Rooster crowing]
See, our eyes perceive light in a range of wavelengths. Different wavelengths produce different color sensations and those sensations help tune your internal clock. Here's sleep researcher Brian Zoltowski.
Professor Brian Zoltowski: One of the best biological cues we have to what time of day it is, is light and it turns out that blue light, in particular, is very effective for basically predicting when morning is.
Narrator: And guess what puts out a ton of blue light?
Professor Zoltowski: Your iPad, your phone, your computer, emit large quantities of blue light.