What's keeping you up at night?

If you're like most people--kids and adults alike--it's almost certainly some kind of screen, from the big one in the living room to the little one that's never far from your hand.

Now, a new study finds that more than a third of all Americans get less than seven hours of sleep a night--and at the same time, a new survey finds that up to 95 percent of us are in front of those glowing screens within an hour of bedtime.

Are the two related? Almost certainly, and here's why:

First, you get "sucked in." Once you turn on the tube, start playing a game or begin surfing the Web, it's easy to lose track of time.

Next thing you know, it's well past midnight... and you're not even tired.

And that's because--second--all those glowing lights can actually disrupt the production of the sleep hormone melatonin... making it harder to get the rest you need, even after you shut of all the lights, big and small.

And that can lead to huge problems during the daytime.

In another new study, researchers found that a quarter of all people who get less than seven hours of sleep a night have trouble concentrating.

Another 18 percent said they had memory problems... while 8.6 percent said they were so tired all day they didn't do their jobs very well, according to the U.S. Centers for Disease Control and Prevention.

If only offices had nap rooms!

Actually, that's not such a bad idea.

In fact, it's a win-win: Studies have found that daytime naps can enhance productivity, boost memory and learning, and lower the risk of burnout.

That's the win for your boss.

But there's also a win here for you--because in addition to catching up on sleep, you might also lower your blood pressure: A new study finds a significant drop among people who take a 45-minute nap during the day.

Maybe office cubicles should come with pillows, blankets, and inflatable mattresses along with computers, phones and spinning chairs.