A new study, published in the journal "Optometrist and Vision Science," suggests that reading text on hand-held devices can cause headaches and other symptoms.
"The fact that people are holding the devices at close distances means that the eyes have to work that much harder to focus on the print and to have their eyes pointed in right direction," said study co-author Dr. Mark Rosenfield.
"We spend a lot of time on computers. We're computerized all day long and we sometimes go home with a little bit of eye strain," said optometrist Jeffrey Hankin.
According to the research, more than three quarters of us are plugged into the Internet, and 90 percent of us are getting eye strain.
"Far-sighted people are the people that typically don't wear glasses for distance until they hit their 40s," Hankin said. "Those people will get some eye strain as they use their eyes more and more on a smart phone, especially very close."
There is no evidence that reading small text causes permanent damage to the eyes but a couple of simple tips may help: increase the font size on your device, and hold the device at least six inches from your eyes.