Lenses ease computer eye strain

Staring at a computer or smartphone screen can cause a variety of vision problems, but special-purpose glasses can help bring the screens into sharp focus, reports Mickey Meece

If I moved my computer monitor close enough to see the screen clearly, it was nearly in my lap. If I left the monitor where it should be, I had to lean forward awkwardly. During my annual eye exam, I told my optometrist about my workstation discomfort and the strain it was causing my eyes, neck and back.

Eyestrain, headaches, blurred vision, dry eyes, and neck and shoulder pain are common complaints of someone experiencing computer vision syndrome, according to the American Optometric Association.

If you optimise your work environment for comfort and still have problems, the solution may be another pair of glasses, the association says. Normally, I’d be sceptical of a trade association suggesting that I buy more of their wares. But studies have found that a majority of people who work on computers or hand-held devices experience some vision problems, the association said.

With 31 percent of those over 18 saying that, on average, they now spend at least five hours a day on a computer, tablet or smartphone, it appears that these symptoms will only become more common.

Many of those people need special-purpose glasses with lenses adjusted to bring the computer screen sharply into focus. The problem with computer work is twofold, said Gary Heiting, an optometrist and associate editor of AllAboutVision.com, a consumer information site.

“During computer use,” Heiting said, “our eyes not only have to stay focused but also have to stay properly converged for long periods of time,” referring to the ability to move both eyes inward. The glasses people use for driving or the ones they use for reading books often have the wrong focal point for computer use or are ill-suited for computer use.

This convergence fatigue can cause eyestrain and blurred vision, just as focusing fatigue does, he added. What is more, computer workers blink much less frequently than they would during a face-to-face conversation, and that leads to dry eyes at work.

Computer vision syndrome originated with office work, but the popularity of mobile devices is now straining the eyes in a different way, according to James E. Sheedy, director of the Vision Performance Institute at Pacific University in Oregon.

To avoid strain on mobile devices, Sheedy said, make the print size larger, read for shorter periods and employ the 20-20-20 rule. For every 20 minutes of using the device, take a 20-second eye break and look at something beyond 20 feet. “This gives your eyes time to relax,” he said. “It’s almost like flexing your muscles.”

If that does not work well enough, consider the glasses. Computer glasses can take several forms, according to Heiting, depending on the patient’s age and visual needs. “Resist the temptation to buy over-the-counter reading glasses for use as computer glasses,” he said.

For adults under 40 who have not yet experienced the normal age-related loss of near-focusing ability, called presbyopia, single-vision lenses are typically used for computer glasses, Heiting said. For people with presbyopia, doctors often prescribe single-vision, bifocal, trifocal or progressive lenses (without lines), depending on the wearer’s need, he added.

Heiting prefers single-vision eyeglasses specifically prescribed for computer and desk work.

“This is what I wear myself with great success,” he said. Most computer glasses will cause blurred or limited distance vision and should not be worn for driving or other tasks that require clear distance vision, he added.

But some people may prefer bifocals customised for computer and desk work. Lens adjustments might include a larger-than-normal reading zone that is placed higher in the lens to eliminate head-bobbing.

For people with more advanced presbyopia, special-purpose bifocals may be a good option. The top part of the lens is for using a computer (intermediate vision) and the bottom part has added magnification for reading or using a cellphone.

Trifocals for computer work typically have a larger-than-normal intermediate zone placed higher in the lens for more comfortable viewing of the computer screen, but they still contain a small zone in the top of the lens for distance viewing.

People, who do not like the line on their lenses calling attention to their need for bifocals (and their age), may find relief with progressive lenses. There are two types of progressive computer lenses: those prescribed for computer use for older adults who are presbyopic and those prescribed for younger adults who are not.

Young adults are sometimes prescribed progressive lenses with a limited amount of added magnification for intermediate and near vision to reduce the amount of focusing the eye has to do to see a computer or smartphone clearly for long periods of time.

Presbyopic computer users can find specially designed progressive lenses from Carl Zeiss Vision, including the Zeiss Business and Gradual RD lines, the Shamir Office lens from Shamir (which also sells a fatigue-relief lens) and the Seiko PCWide from Seiko Optical.
But you certainly don’t have to look for custom glasses. You can make do with frames and lenses at your local or national eyeglass store as I did.

During my exam, the doctor tested me for near- and farsightedness, as usual, but then he asked me how far I wanted the computer from me – I said about an arm’s length away. He moved the eye chart to a distance of about 20 inches away.

After the usual routine (“Can you see better with No. 1 or No. 2, 3 or 4?”), he jotted down the prescription for computer glasses. I thought we were finished, but then he asked, “Do you read printed documents as well while you are working at the computer?”
I said I did, and that I also often reached for my smartphone and my tablet. I could see where this was going, and it would cost me: Not only did he recommend computer glasses, but he also thought they should be bifocals.

I headed to a nearby LensCrafters and found some frames on sale. (I did not care how stylish the glasses were, as they would never leave my office.) I also added an anti-reflective coating to my bifocals to cut down on glare, which is a must for computer work.

As I sat for my fitting, the technician said, “Oh, you must be a computer engineer.”
“I wish,” I said as I read the receipt. Even with the lenses discounted by half, I still owed $288. “How much would they have been without the bifocals?” I asked. He said I would have saved $70.

After a few weeks of wear, the computer glasses worked as promised. I moved the monitor away from my lap and I can now sit back comfortably in my ergonomic chair. The bifocals, on the other hand, are taking some getting used to because it is now hard to read the keyboard.

The good news is that LensCrafters has a 90-day unconditional guarantee, so I may be headed back for a refund or a replacement pair without the bifocals.

The New York Times