Joanne Reitano is a professor of history at LaGuardia Community College in Long Island City, Queens. She writes wonderful books about the history of the city and state, and has recently been spending many hours — sometimes all day — at her computer to revise her first book, “The Restless City.” But while sitting in front of the screen, she told me, “I developed burning in my eyes that made it very difficult to work.”

乔安·雷塔诺(Joanne Reitano)是皇后区长岛市拉瓜地亚社区学院(LaGuardia Community College)的历史教授，著有若干关于长岛市和纽约州历史的佳作。近来她花了大量时间——有时是一整天——坐在电脑前，修改她的第一本书《不安之城》(The Restless City)。但她告诉我，坐在屏幕前的时候，“我眼睛里有灼烧感，很难好好工作。”

After resting her eyes for a while, the discomfort¹ abates², but it quickly returns when she goes back to the computer. “If I was playing computer games, I’d turn off the computer, but I need it to work,” the frustrated³ professor said.

让眼睛休息一阵子，不适感会消失，但等到她重新回到电脑前，很快又会感到不适。“如果是在玩游戏，那我会关掉电脑，但我要用它来工作啊，”雷塔诺沮丧地说道。

Dr. Reitano has a condition called computer vision syndrome⁴. She is hardly alone. It can affect anyone who spends three or more hours a day in front of computer monitors, and the population at risk is potentially huge.

雷塔诺得了电脑视觉综合症。她并非孤例。任何每天花三个小时或更多时间对着电脑显示器的人，都有可能患上，受其威胁的潜在人群规模庞大。

Worldwide, up to 70 million workers are at risk for computer vision syndrome, and those numbers are only likely to grow. In a report about the condition written by eye care specialists in Nigeria and Botswana and published in Medical Practice and Reviews, the authors detail an expanding list of professionals at risk — accountants, architects, bankers, engineers, flight controllers, graphic⁵ artists, journalists, academicians, secretaries and students — all of whom “cannot work without the help of computer.”

在全世界，可能患上电脑视觉综合症的人多达7000万，这一数字只会越来越大。尼日利亚和博茨瓦纳的眼部护理专家撰写了一篇关于该病症的报告，并发表在了《医疗实践与评论》(Medical Practice and Reviews)上。报告作者详细列出了可能会患上电脑视觉综合症的专业群体——会计师、建筑师、银行家、工程师、空管员、平面设计师、记者、学者、文秘和学生——这一名单正日益扩大，所有这些人“离开电脑的帮助就无法工作”。

And that’s not counting the millions of children and adolescents who spend many hours a day playing computer games.

这还没算上成百上千万每天花很多个小时玩电脑游戏的儿童和青少年。

Studies have indicated 70 percent to 90 percent of people who use computers extensively, whether for work or play, have one or more symptoms of computer vision syndrome. The effects of prolonged computer use are not just vision-related. Complaints include neurological symptoms like chronic⁶ headaches and musculoskeletal problems like neck and back pain.

研究显示，在工作或娱乐中经常使用电脑的群体，有70%至90%的人会出现一种或多种电脑视觉综合症的症状。长时间使用电脑不仅会造成视觉方面的影响，其他后果还包括慢性头痛等神经性症状，以及颈部、背部疼痛等肌肉骨骼问题。

The report’s authors, Tope Raymond Akinbinu of Nigeria and Y. J. Mashalla of Botswana, cited four studies demonstrating that use of a computer for even three hours a day is likely to result in eye symptoms, low back pain, tension headache and psychosocial stress.

前述报告的作者——尼日利亚的托普·雷蒙德·埃金比努(Tope Raymond Akinbinu)和博茨瓦纳的Y·J·马沙拉——引用的四项研究成果显示，即便每天使用电脑三小时，也有可能带来眼部症状、腰痛、紧张性头痛以及社会心理压力。

Still, the most common computer-related complaint involves the eyes, which can develop blurred⁷ or double vision as well as burning, itching⁸, dryness and redness, all of which can interfere⁹ with work performance.

不过，与电脑有关的最常见症状是眼部不适，包括视线模糊、重影，以及灼烧感、瘙痒、发干、发红等，所有这些都有可能影响工作表现。

One reason the problem is so pervasive¹⁰: Unlike words printed on a page that have sharply defined edges, electronic characters, which are made up of pixels, have blurred edges, making it more difficult for eyes to maintain focus. Unconsciously, the eyes repeatedly attempt to rest by shifting their focus to an area behind the screen, and this constant switch between screen and relaxation¹¹ point creates eyestrain and fatigue¹².

这一问题之所以如此普遍是因为：不同于印在纸张上边界清晰的文字，由像素组成的电子字符边界模糊，让人眼难以维持焦点。不知不觉中，眼睛会反复试图把焦点切换到屏幕后方的某个区域，以获得放松，而在屏幕和放松点之间的不停切换，会导致眼部疲劳。

Another unconscious effect is a greatly reduced frequency of blinking, which can result in dry, irritated eyes. Instead of a normal blink rate of 17 or more blinks a minute, while working on a computer the blink rate is often reduced to only about 12 to 15 blinks.

另一个不易被察觉的影响是眨眼频率大大降低，从而可能导致眼睛干涩、过敏。正常的眨眼频率是每分钟17次，但在电脑前工作时，常常会下降到12至15次。

But there are additional problems. The head’s distance from the screen and position in relation to it are also important risk factors. To give the eyes a comfortable focusing distance, the screen should be about 20 to 26 inches away from the face. The closer the eyes are to the monitor, the harder they have to work to accommodate to it.

但还有其他方面的问题。头部和屏幕之间的距离以及两者之间的方位关系同样是重要的风险因素。要让眼睛舒适地聚焦，屏幕和面部之间的距离应保持在20至26英寸左右（约合51至66厘米）。眼睛离屏幕越近，就越难以做出调整去适应屏幕。

In addition, when looking straight ahead, the eyes should be at the level of the top of the monitor. The University of Pennsylvania’s ophthalmology department advises that the center of the monitor should be about four to eight inches lower than the eyes to minimize dryness and itching by lessening¹³ the exposed surface of the eyes because they are not opened wide. This distance also allows the neck to remain in a more relaxed position.

此外，当望向正前方的时候，眼睛应与显示器顶端平齐。宾夕法尼亚大学(The University of Pennsylvania)眼科学系建议，显示器中心应比眼睛低4至8英寸左右（约合10至20厘米），以尽量减少眼睛干涩和瘙痒的症状，因为这样的话就不用把眼睛睁得太大，眼球暴露在空气中的面积就会减少。

Yet, in a study in Iran of 642 pre-university students reported in Biotechnology and Health Sciences last year, 71 percent sat too close to the monitor for comfort, and two-thirds were improperly¹⁵ positioned directly opposite or below the monitor.

不过，伊朗的一项以642名高中生为对象的研究显示，71%的人坐得离显示器过近，好让自己更舒适一些；三分之二的人以不恰当的方式正对着显示器，或者坐得比显示器低。这项研究的结果于去年发表在了《生物技术与健康科学》(Biotechnology and Health Sciences)上。

Improper¹⁴ lighting¹⁶ and glare are another problem. Contrast is critical, best achieved with black writing on a white screen. The screen should be brighter than the ambient light — overly bright overhead light and streaming daylight force the eyes to strain to see what is on the screen. A bright monitor also causes your pupils to constrict¹⁷, giving the eyes a greater range of focus.

不恰当的照明和炫光也会成为问题。对比很关键，白色屏幕与黑色字迹的对比最为强烈。显示器应该比环境光亮一些——过亮的顶灯或者强烈的阳光，会迫使眼睛非常用力地望向屏幕。明亮的显示器还会让瞳孔收缩，从而让眼睛的聚焦范围更大。

You might need to reposition the desk, use a dimmer switch on overhead lights, or lower window shades to keep out sunlight. In addition, using a flat screen with an antiglare cover, and wearing glare-reducing or tinted¹⁸ lenses can help to minimize glare.

你或许需要调整桌子的位置，给顶灯安装调光开关，或者拉下遮光窗帘，把阳光挡在外边。此外，使用贴有防眩光膜的平面屏幕，佩戴防眩光或有色眼镜，也有利于最大程度地减少炫光。

Be sure to use a font size best suited to your visual acuity¹⁹, and have your eyes examined regularly — at least once a year — to be sure your prescription²⁰ is up-to-date. This is especially important for people older than 40 and for children who are heavy users of computers because visual acuity can change with age. Make sure, too, that your monitor has a high-resolution display that provides sharper type and crisper images. And clean the monitor often with an antistatic dust cloth.

一定要使用最适合自身视力的字体，并定期检测视力——至少一年一次——以便根据最新的状况采取对策。这一点对40岁以上的成人和经常使用电脑的儿童尤为重要，因为视力会随着年纪的增长而出现变化。还要确保你的显示器配备了高分辨率的屏幕，从而让画面更清晰。此外，要经常用防静电除尘布擦拭显示器。

Those who work from printed materials, moving back and forth²¹ from them to the screen, could minimize neck strain by mounting documents on a stand next to the monitor. If, like me, you use many different printed documents at the same time, consider getting special computer glasses — bifocal or progressive lenses with the upper portion ideal for screen reading and the lower designed for print distance.

如果工作内容涉及印刷品，目光要在印刷品和屏幕之间来回切换，不妨在显示器旁安一个摆放文件的支架，以便尽量减少颈部疲劳。如果你像我一样，要同时使用不同的印刷资料，不妨考虑购买特殊的电脑眼镜——其双光或渐进式镜片的上半部分适合看屏幕用，下半部分则适合看印刷品。

While prevention is most important, if you already have symptoms of computer vision syndrome, there are ways to reduce or eliminate them. Ophthalmologists suggest adhering to the “20-20-20” rule: Every 20 minutes, take a 20-second break and look at something 20 feet away.

预防是重要的，但你如果已经有了电脑视觉综合症的症状，也可以采取一些办法来缓解或消除它们。眼科医生建议遵循“20-20-20”法则，每隔20分钟，休息20秒，望向20英尺（约合6米）远的地方。

Consciously blink as often as possible to keep eye surfaces well lubricated. To further counter dryness, redness and painful irritation²², use lubricating eye drops several times a day. My ophthalmologist recommends products free of preservatives²³ sold in single-use dispensers.

要有意识地尽可能经常眨眼，以便让眼球表面保持润滑。要进一步应对发干、发红以及让人难受的过敏症状，一天可以点几次眼药水。我的眼科医生推荐购买不含防腐剂的、供单次使用的小包装产品。

You can also reduce the risk of dry eyes by keeping air from blowing in your face and by using a humidifier to add moisture to the air in the room. And Dr. Reitano said her eye doctor also suggested applying warm moist compresses to her eyes every morning.

为了防止眼睛干涩，你还可以避免让风直接吹到脸上，并使用加湿器，让房间里的空气更加湿润。雷塔诺说，她的眼科医生还建议她每天早上对眼部进行湿热敷。