Computer Vision Syndrome is a medical condition associated with our addiction to digital devices -- from computers to smart phones, hand-held video games and e-books. Doctors estimate that nearly 80 million people in the U.S. could suffer from it.  And that does not include the growing number of children developing eye problems related to electronic devices. 

If you spend more than three hours a day in front of a computer or electronic terminal you probably have some level of what physicians are calling "Computer Vision Syndrome."  Dr. Michael Duenas is with the American Optometric Association. "It causes fatigue, it can cause headaches, neck ache, back ache and it can cause things like diplopia or double vision and intermittent blur vision," he explained.

"This isn't damaging the eyes, is not producing a disease like we would talk about glaucoma or diabetic retinopathy, it's not a disease like that," Dr. Rachel Bishop added. She is chief of consulting services at the National Institutes of Health in Washington. "It is surface dryness and is eye strain from focusing."

Dr. Bishop says studies show that people do not blink as much when they are concentrating on a computer task, and that causes dryness and fatigue. "There is a muscle in the eye that focuses the eye on whatever you are looking at. The computer terminal is typically further away from a book, and if your focus continues for hours, that muscle tires," she said.

Dr. Duenas says the syndrome can cause low productivity in adults and learning disabilities and low grades among school children. "The fact is that even children now are on computer terminals for long periods of time, and many are playing games using hand held devices that put strain on their vision system," Dr. Duenas said.

Doctors agree that looking at an electronic screen is different from looking at printed material.  Printed material has greater contrast while electronic screens are more difficult to bring into focus and require more effort.

"It does have to do with optimizing contrast, optimizing lighting and decreasing disturbances like glare disturbance that can cause strain," Dr. Bishop said.

But  Dr. Duenas says data show youngsters having increasing problems. "We are finding now more and more children are becoming nearsighted," he said, "because of the excessive close work on hand held devices."

Doctors say some easy steps can deal with many of the problems.  For example, occupational glasses. "There is a new kind of glasses called occupational glasses," Dr. Bishop said, "where instead of the traditional distance glasses at the top and near or intermediate glasses below, which is bi-focal or tri-focal, they put the computer distance glasses at the top because that's typically where we are looking out of our glasses and the reading glasses below."

Doctors also recommend using eye drops for lubrication and taking a break every 15 minutes to look into the distance.  and one more thing.  "Make sure that the height of the computer terminal is at the right height," Dr. Duenas said. "You want it at about 4 inches [10.2 cm] below your line of sight.  You don't want to be looking up at a computer terminal."

Although the solutions seem simple, doctors expect Computer Vision Syndrome will get worse as more movies and television programs become available on computer and with the growing number of small electronic devices.