Ophthalmologists are discovering once again that technology can be a double-edged sword, as society's growing dependence on computers appears to contribute to dry eye syndrome.
"People who read a lot and particularly, I think, those who stare at computers tend to blink less, and it does seem to be associated with eye irritation and dry eye," said William Mathers, MD, Casey Eye Institute, Oregon Health Sciences University, Portland.
"There's nothing special about a computer, but it's a situation where a lot of people spend a lot of time concentrating and not blinking, so it brings out dry eye symptoms a lot more than just sitting around and chatting with friends," concurred Philip Paden, MD, Paden Eye Care, Medford, OR.
Patients may not relate dry eye symptoms to other periods of heavy concentration in which they can occur, such as reading or driving in fog, but they immediately grasp the connection between burning, itching, sensitive eyes, and the time spent in front of the monitor now that computer use is widespread in home, office, and educational settings, Dr. Paden said.
The result of this intensive concentration on the computer screen and the associated lower blink rate is loss of water, he continued.
"When the eyes are open and evaporation changes the tear film, the only thing that leaves is pure H2O," Dr. Paden said. "The lipid layer is still there, the mucin layer is still there, and all of the growth factors, enzymes, and antibacterial proteins are all still there; there's just not enough water."
There are various ways to address the evaporation that causes computer-related eye irritation, including such simple tasks as closing your eyes for a minute or two or taking a break from staring at the screen to look briefly at other items in the room at varying distances, but these steps may be difficult to remember for people concentrating on their work or caught up in a game.
People also can use products intended to treat dry eye, such as artificial tears or mist. Replenishing the tear film with these products causes improvement on several levels.
"If you make the eye feel better, you lower the level of stress to the surface, and that improves the whole situation," Dr. Mathers said. "Not only does the eye feel better, but it functions better, and that probably then results in better tear production circumstances too. A lot of dry eye is a stress response that feeds on itself. The eye is stressed, the stress induces a more-dry eye, and that causes further stress. You have to break that cycle."
However, some people find it awkward or inconvenient to stop working and apply drops, especially in a highly visible office setting, Dr. Paden said.
As an alternative to treating the blurring and burning associated with computer use, he suggests Nature's Tears Eye Mist (Bio-Logic Aqua Technologies), which can be sprayed across the eyes in a sweep lasting just a second or two.
"It's tremendously more convenient than stopping and putting in eyedrops," he said.
Eyedrops wash away the tear film and replace it with a solution intended to mimic natural tears, but this also may eliminate essential components of the tear film, Dr. Paden said.
While a large quantity of pure water cannot be added to the surface of the eye because it would cause osmotic shock, an application of Nature's Tears is safe because it contains a minute quantity of water in mist form, Dr. Paden said. A spray lasting a couple of seconds adds about 1 μl of pure water to the eyes, replenishing the thickness and concentration of the aqueous layer.
"The lipid layer is still there to retard evaporation, all of the beneficial proteins are still there, and the mucin layer is still there. We have not replaced your tear film with all of that complex chemistry and structure associated with artificial tears. We have replaced the evaporated water and left all the good stuff there. Nothing else works that way. It's fundamentally different from other available dry eye products," Dr. Paden said.