Mobile Devices Can Strain the Eyes
Computer screen, smartphone, e-reader, iPad - the number of electronic devices Americans stare at daily continues to grow. And the smaller the screen, the harder their eyes have to work.
Many people hold their cell phone close up to read or send text messages or surf the Web while on the go. Those closer distances - ranging from 7 to 14 inches away - can cause eyestrain, dry eye, and blurred vision, according to researchers at SUNY State College of Optometry in New York City.
The researchers observed two groups of volunteers and how they used their mobile devices. The first group of about 130 volunteers, with an average age of about 23, was asked to hold their smartphone and read an actual text message. Researchers measured the distance between the phone and participants' eyes. They also recorded the font size used for the display.
A second group of volunteers - 100 people with an average age of about 25 - had their phone-to-eye distance measured while looking at web pages.
The volunteers who read text messages held their phone seven to 14 inches from their eyes. Those who looked at web pages held their phone an average of a little over a foot from their eyes.
When the researchers looked at font size for both text messages and web pages on the phone, they found that text messages were about 10 percent larger than the font size on a typical page of a newspaper, but the font size on web pages was much smaller - from 80 percent of the size down to just 30 percent.
One way to ease possible eyestrain when using mobile devices is to boost the font size.
Adjusting font size on an e-book reader is usually easy to do. For other handheld devices, "the problem is to figure out how to do it," says Scott MacRae, M.D., at the University of Rochester Medical Center, in Rochester, N.Y.
If you're a regular computer user, try using Verdana 12-point font, the only font designed specifically for computers, Dr. MacRae says.
Always talk with your health care provider to find out more information.
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