A growing number of Americans, including nearly 70% of teens, are paying attention to multiple screens at once, according to a new survey by the Vision Council. That puts even more people in danger of digital eye strain, with symptoms such as dry or irritated eyes, blurred vision, headaches and neck or back pain—after staring at a screen for hours. What are some solutions? Printing out pages to read off screen is one analog solution, but you can also consider the 20-20-20 rule: for every 20 minutes with your screen, give your eyes a 20 second break and look 20 feet away, which will relax the focusing muscles.