Today's teachers make full use of computers, interactive whiteboards, digital devices, and even 3D technology to enhance the learning environment. Forty percent of teachers use computers for instruction, and at least one computer is in 97% of all American classrooms. That adds up to a lot of screen time for kids who also watch TV or play on the computer at home. But is it harmful to a child’s vision?
Parents are worried. Nearly a third say they’re concerned that computers and handheld electronics may damage their child’s eyesight. And 53% of parents believe 3D viewing may be harmful, according to a survey by the American Optometric Association (AOA).
What does science say? So far, no evidence-based study has found that new technology itself causes vision problems, other than eye fatigue. Yet a 2009 study showed that the number of people with nearsightedness (myopia) has increased from 25% to nearly 42% in the last 30 years.
One theory: Today’s kids spend far more time doing "near work," such as texting, looking stuff up on cell phones, and playing computer games. And the increased time spent looking at things close up may have an effect. Other possible factors may include genetics and lack of outdoor activity.
Eyestrain and New Technology: Old Worries in a New Age
"It used to be, 'if my child reads for too long, if my child reads too small print, if they hold the book too close, is that going to make them nearsighted?'" says Pia Hoenig, OD, MA, FAAO, associate clinical professor and chief of the Binocular Vision Clinic at UC Berkeley. Now parents are asking the same questions about computers, smart phones, and 3D.
But most vision experts say parents can rest assured, as long as they apply commonsense rules to how much time their children spend on electronic devices.
"These new technologies are challenging our visual system," says James E. Sheedy, OD, PhD, director of optometric research at the Vision Performance Institute and professor of optometry at Pacific University in Oregon. But there is no evidence that they actually damage the eyes. "There really is nothing to fear," Sheedy says.
Hoenig agrees: The key "is not to stop kids from using electronics -- there are too many pluses. It's to use them wisely."
How Digital Devices Affect Your Eyes
"I think all these new technologies are pretty wonderful," says Sheedy, who is also a technology and vision expert with the American Optometric Association. But, he says, there are things we need to be aware of.
- Handheld devices cram a lot of text onto a very small screen. In order to see the small print, we need to hold it close to our eyes. "There's a muscle inside the eye that contracts so that you can focus," Sheedy says. At the same time, your eyes also need to cross, or come together. This can cause fatigue and eyestrain. So parents should advise kids to use handheld devices only for quick tasks, such as texting. Don't use them to read articles or documents, Sheedy says.
- Computers bring up a different issue, Sheedy tells WebMD. "One of the things about a computer is that the display is fixed on the desk.” With a magazine or book, we may flop down on the couch, put our feet up, or shift around a lot while we read. At a computer we sit for long periods in still, static positions. “And for kids, very often the work space and the sizes of the tables are not well-designed for them," he says. This can cause neck and back pain.
- Also, looking at a computer for long periods of time really fatigues the eyes, Sheedy says. This can result in eyestrain, headaches, dry eyes, blurred vision, and trouble seeing far objects, a condition called computer vision syndrome. These symptoms usually go away once you stop using the computer.
How You Can Help Prevent Eyestrain
You can help your child prevent eyestrain, as well as neck and back pain, by taking these steps:
- Place the screen between 20 to 28 inches away from your child's eyes. Align the top of the screen at eye level so that children look down at the screen while they work.
- Use low-watt bulbs in lighting fixtures as well as drapes or blinds to reduce glare from windows.
- Choose a comfortable, supportive chair positioned so that the child's feet are flat on the floor.
- Encourage children to move around and change positions while working.
- Suggest that they limit leisure screen time to two hours or less a day. This includes watching TV, playing video games, and using mobile phones.
- Teach kids to rest their eyes. Every 20 minutes, tell them to look at least 20 feet away for 20 seconds. Also remind children to blink regularly to prevent dry, irritated eyes.
- Take notice if children are squinting, frowning at the screen, or rubbing their eyes, says Hoenig. These are all signs of eyestrain. Make sure their prescription wear is up to date.
- Glasses may be needed for some people with computer vision syndrome. A single or bifocal lens, or tinted lens material, may help increase contrast perception and filter out glare and reflective light to reduce symptoms of eye strain.
Using 3D: The Newest Classroom Technology
3D is an exciting and fun new technology being used in many classrooms all across the country. Sheedy, along with other vision health experts, was involved in the recent AOA report, "3D in the Classroom: See Well, Learn Well." It conclusively states that watching 3D images does not harm children's eyesight. In fact, says Sheedy, "viewing 3D is actually a pretty good screening mechanism for people who've got vision problems."
In order to see something in 3D, each eye needs to process a separate image, Sheedy explains. The 3D glasses help us do that. Your eyes need to converge, or come together, to see the 3D objects that appear closer to you, yet your focus remains on the main display screen. This challenges our eye coordination and eye focusing skills. Thus, it can reveal weaknesses in our vision that aren't detected in simple vision tests.
While the majority of people don't have problems viewing 3D, some experience eyestrain, headaches, nausea, discomfort, or dizziness, says Hoenig. Others just can't see the 3D images. This may be a sign of eye health problems such as lazy eye, poor focusing and coordination skills, or vision misalignment. Hoenig and Sheedy both recommend that parents ask children how they feel after viewing 3D. If the child complains of any of these symptoms, schedule an appointment for a full eye exam that includes testing eye coordination and focusing skills. The good news is that most of these children's vision problems can be treated with glasses or contact lenses.
Both experts also suggest having an eye exam at the beginning of each school year. "At this time of year when you're buying notebooks and school clothes, you ought to be thinking of getting the eyes ready for school," Sheedy says. "The eyes are pretty important to the learning process."