Our eyes are on everything from laptops and

3-D movies to smartphones and GPS units. And it's not just adults typing away at a computer all day; students use technology throughout the school day.

In New Canaan, and in several schools in Fairfield County, students are using iPads, laptops and SMART Boards. At some point, we've all heard warnings to not read in the dark or not to sit too close to the television. So, what effect does current technology have on our vision?

Leading experts in the field say there is no negative effect, but that hasn't stopped parents from being concerned, especially with new emerging 3-D technology.

According to a 2009 survey by the American Optometric Association, 53 percent of parents believe 3-D viewing may be detrimental to their children's vision.

"Parents are just too concerned about eyes and new technologies they are unfamiliar with. Using your eyes is never a bad thing and `eye strain' or overuse is an urban legend," said Dr. Nils Loewen, an assistant professor of ophthalmology and visual science at Yale University. "There simply is no harm.

"Well meant limitation of smartphones/Game Boys/PlayStations makes sense to allow children to learn the importance of real world conversations and interactions or just to be able to go to bed. But just as my parents were wrong that reading in the dark when in bed is bad for the eyes, using electronic gadgets or games is not doing any harm."

Loewen said much of the resent reaction to 3-D has stemmed from the new Nintendo 3DS handheld video game system, which he says is perfectly safe to use.

"A more recent concern was directed at the 3-D Nintento and the development of stereovision in young children. That company got so concerned about being held responsible for poor eye sight in young children that they recommended not to use it," Loewen said. "There is no reason to assume it would be harmful. It is an exercise in stereopsis (stereovision) that is not affecting our closest cousins, monkey children," according to a New York Times article by Matt Richtel in January.

Still, the "eye strain" or fatigue that Loewen dismisses as myth was studied in a recent report by the Journal of Vision called "The zone of comfort: Predicting visual discomfort with stereo display."

According to the study, there are numerous potential causes of visual discomfort when viewing stereo displays. These include discomfort due to the eyewear required to separate the two eyes' images, ghosting or crosstalk between the two images, misalignment of the images, inappropriate head orientation, vergence-

accommodation conflict, visibility of flicker or motion artifacts, and visual-vestibular conflicts.

Basically, the illusion played on your eyes convincing you the image your see is 3-D causes discomfort, but does not hurt your vision, staying in line with Loewen's remarks that your eyesight won't worsen because of technology. He said there is no correlation. In fact, Loewen said outdoor activities away from the silver screens are more probably dangerous for eyes.

"Parents should be much more concerned about outdoor activities and make their children wear protective sunglasses; I recommend ones that are made out of shatterproof polycarbonate material that block UV light and wrap around the eyes. There is good scientific evidence that UV exposure is a risk factor for damage to the surface of the eye (the cornea), the lens and the retina," he said. "Specifically, UV exposure can promote an abnormal growth of the conjunctiva called `pterygium', cataract formation and macular degeneration as well as more acute retina photo-damage. Damage is accumulative over time. In animal experiments any blue light below 400 nanometers wavelength can cause damage to the retina and our eyes are very similar."

Sunglasses, Loewen said, are perhaps one of the more under-used protective agents against eye trauma since they are more often seen as a fashion statement these days.

"The other, almost more important feature of polycarbonate lenses, is very good eye protection against impact. In the summer we are much more likely to (have) ocular trauma with all the outdoor activities. Such eye trauma can be devastating. Protection is very important for anyone active, especially for children and mandatory for patients with only one eye," Loewen said. "Any activity in water in the summer and snow in the winter means that more light is reflected into the eye. For full protection make sure they wrap around the eye in a close fit to shield against UV, dirt particles and trauma. The best thing about the right sun glasses is that you an fully enjoy your time outside and not worry. I use them all the time myself."

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