Eyestrain, headaches, blurred vision, dry eyes, and neck and shoulder pain are common complaints of someone experiencing computer vision syndrome.
眼睛疲勞、頭痛、視線模糊、眼乾、頸肩疼是電腦視覺症候群常見的症狀。

The solution may be another pair of glasses. Studies have found that a majority of people who work on computers or hand-held devices experience some vision problems, the American Optometric Association says.
另配一副眼鏡可能是解決之方。美國視光學會指出，研究顯示，工作時必須長時間使用電腦或手持裝置者泰半會有視覺問題。

Today, 31 percent of those over 18 say they spend, on average, at least five hours a day on a computer, tablet or smartphone.
今天，年逾18歲者31%表示平均每天至少花5個小時盯著電腦、平板電腦或智慧手機的螢幕。

Many people need special glasses with lenses adjusted to bring the computer screen sharply into focus. “During computer use,” said Gary Heiting, an optometrist and the associate editor of AllAboutVision.com, a consumer information site, “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. Glasses for driving or for reading books can have the wrong focal point or are otherwise ill suited for computer use.
許多人須戴鏡片經過調整的特殊眼鏡才能把電腦螢幕看得十分清楚。消費資訊網站AllAboutVision.com副主編、視光專家海丁說格：「使用電腦時，我們的兩眼不只要不斷聚焦，還得長時間保持適度輻輳會聚（兩眼向內移動）的狀態。」。開車或閱讀使用的眼鏡可能焦點不對，或者不適合用電腦時戴。

Convergence fatigue can cause eyestrain and blurred vision, just as focusing fatigue does, Dr. Heiting added. And computer workers blink much less frequently than they would during a face-to-face conversation, and that leads to dry eyes.
海丁說，會聚疲勞就和聚焦疲勞一樣，會引起眼睛疲勞與視線模糊。另外，盯著電腦工作眨眼頻率遠低於當面對話，導致眼睛乾澀。

Mobile devices strain the eyes in a different way.
行動裝置以不同的方式使眼睛疲勞。

To avoid the problem, said Dr. James E. Sheedy, director of the Vision Performance Institute at Pacific University in Oregon, increase the print size, read for shorter periods and use 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.
奧勒崗州太平洋大學視覺表現研究所所長薛迪指出，避免這個問題的方法包括加大字體、縮短閱讀時間，以及謹記20-20-20原則。也就是每使用裝置20分鐘就讓眼睛休息20秒，望向20英尺（6公尺）以外的東西。他說：「讓眼睛有時間休息。」

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, Dr. Heiting said. For people with presbyopia, doctors prescribe single-vision, bifocal, trifocal or progressive lenses (without lines), depending on the wearer’s need.
海丁說，不到40歲，尚無與年齡有關的常見近距離聚焦能力喪失問題，也就是老花眼的成年人，電腦專用眼鏡通常使用單焦鏡片。已老花者，醫師通常會依需要使用單焦、雙焦、3焦或漸進式鏡片（無分隔線）。

Dr. Heiting, who says to avoid using drugstore reading glasses for computer work, prefers prescription single-vision glasses specifically for computer and desk work. “This is what I wear myself with great success,” he said.
使用電腦時，海丁不用藥妝店賣的現成閱讀眼鏡，他愛用專供電腦與書桌上工作使用的處方單焦眼鏡。他說：「我是這麼用眼鏡，效果超好。」

Most computer glasses can cause blurred or limited distance vision and should not be worn for driving or other tasks requiring clear distance vision, he added.
他說，多數電腦眼鏡可能有遠距離視覺模糊或受限問題，開車或從事其他必須看清楚遠距離的工作不宜佩戴。

Some people may prefer customized bifocals. Lens adjustments might include a larger-than-normal reading zone placed higher in the lens to eliminate head-bobbing. For more advanced presbyopia, special-purpose bifocals may be an option. The top part of the lens is for using a computer, and the bottom part has magnification for reading or using a cellphone.
有些人可能喜歡訂作的雙焦鏡片。鏡片調整可能包括在鏡片裡較高部位設置比一般稍大的閱讀區，讓頭部不必擺動。至於老花較深者，專用雙焦鏡片或許是一種選擇。鏡片上半用於看電腦，下半有放大功能，用來閱讀或使用手機。

Trifocals for computer work typically have a larger-than-normal intermediate zone for viewing the computer screen, but they still contain a small zone in the top for distance viewing.
電腦用3焦鏡片通常有大於一般的中間區域，用於觀看電腦螢幕。不過上半部仍然留有一小塊看遠距離的區域。

There are two types of progressive computer lenses: those for older adults who are presbyopic and those for younger adults who are not.
漸進式電腦鏡片有2種：分別供有老花的較年長者，以及尚未老花的較年輕成年人使用。

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.
有時候會為年輕的成年人配製中間與近距離視覺有限放大的漸進式鏡片，以減輕眼睛長時間看清楚電腦或智慧手機承受的聚焦負擔。

And an antireflective coating to cut computer glare is a must.
可降低電腦螢幕刺眼強光的反反射塗層，非有不可。

原文參照：
http://www.nytimes.com/2012/03/15/technology/personaltech/easing-eye-strain-with-the-right-lenses.html

2012-05-22聯合報/G5版/UNITEDDAILYNEWS 陳世欽譯 原文參見紐時週報十版左