We know that sense of impending apocalypse that settles in when you see how much time teens, tweens, and even kiddos are spending glued to a touch screen.

Where will the world be when people can no longer interact without emoticons?

[insert shrug emoticon here]

But hey, you're reading this on a screen (unless you maneuvered to the page and shielded your eyes as you felt around for the print button). So, um, assuming the former, we're going to go ahead and bet that you're down with the fact that computers, tablets, phones, and whatever Apple puts a screen on next (wedding rings? actual apples?) are a part of our lives.

But how big a part? Well, that's what this article's for. So find that print button and carry on.

In our articles on video gaming and screen time (part II), we discuss the hazards and benefits of video gaming as well as just how much screen time is too much. The short answer to that second part: "it depends."

Yeah, sorry.

The slightly longer though by no means exhaustive answer is that when your child's screen time begins to interfere with other aspects of her life—like maintaining relationships, completing homework or chores, or being a civilized and respectful member of your family and community—a line has likely been crossed.

But even if a line hasn't been crossed, it's important to set good boundaries around your child's texting, tweeting, and screen time. Sure, those things are important, and they even can help with communication skills. But those aren't the only skills needed for a child to grow into a well-rounded, thoughtful adult who doesn't experience pseudo-myopia due to excessive time focusing the eyes on images a short distance away.

And so without adding to your own myopia (that is, assuming you're someone who didn't press print), here are some of the limits—and methods for imposing them—recommended by educational and medical experts.

• The American Academy of Pediatrics recommends that children and teens consume no more than 2 hours of entertainment media a day. This new terminology ("entertainment media") replaces the phrase "screen time" in previous AAP guidelines. And that's a recognition that screens are now commonly used for educational purposes and therefore can't be limited in the way they once were. So grin and bear it—some amount of myopia is here to stay.
   
  But that's not all. The AAP does recommend setting up screen-free zones in your home where kids and other family members can gather to read, study, play board games, share meals, and the like away from the screens (whether TV, computer, tablet, phone, iPod, wearables) that have become ubiquitous in today's society.
   
  You can read the AAP's complete policy in the "Media and Children" section of their website.

• Zero to Three, a national nonprofit focused on providing parents and professionals with information about early childhood development, has put out a Screen Sense guide examining the effects of screen time on young children. You can download the complete report, including recommendations, for free.
   
  One of their key findings? That while independent screen usage (think tablet and phone apps) by young children shows no long-term benefit, screen usage that involves parents and children interacting together over the content can actually provide enrichment. Now that's food for thought.

• Finally, it's worth mentioning that the American Medical Association, in its recommendations for assessing, preventing, and treating childhood obesity, suggests that daily screen time should be limited to no more than two hours per day.
   
  That recommendation, however, pre-dates the more recent AAP language shift from "screen time" to "entertainment media," so it's likely the AMA will follow suit when it next updates its policy. Still, since this is about health, it's worth noting that even educational screen time can involve sitting on the couch with a bag of pork rinds. So keep that in mind with whichever set of guidelines you use.

Now that we've hammered out some of the suggestions, let's get into the main arguments against excessive screen time. At the top of the list we've got its implications for three key elements of childhood (and adulthood, come to think of it):

• Physical health. A sedentary lifestyle could lead to problems such as obesity and poor fitness
• Sleep. Screens tend to have a negative impact on sleep quality
• Learning itself. Children appear to learn faster through 3D interactions in the "real world" than they do via screens. Yeah, that's science.

We know—even when you acknowledge these valid and well-researched points, it can be difficult to set limits around your child's screen time. Thankfully, the Mayo Clinic, the National Institutes of Health, and the AMA have recommendations to help you do just that.

Their biggies include:

• Removing TVs from bedrooms
• Setting clear limits, rules, and consequences for going over time—and sticking to them
• Encouraging active screen time (e.g., stretching while watching a favorite program)
• Not eating in front of the TV
• Setting a good example (no more binge-watching Netflix while telling your kids to play outdoors).

You can read more at their respective websites, The Mayo Clinic, the NIH and JAMA (the Journal of the American Medical Association).

Got it? Good.

Now step away from the screen (or the print-out) and go for a walk in the outdoors.