居家辦公傷眼睛嗎？

文/伊索貝爾·惠特科姆 譯/俞月圓

從盡情刷網飛劇集到開Zoom 會議，新冠疫情顯著增加了我們日常生活中盯著屏幕的時間?；ㄔ陔娮釉O備上的時間可能會對眼睛造成負擔。所以，自從開始遠程辦公以來，你可能更頻繁地感到頭痛、眼睛累或視力模糊，并非只有你如此。這些都是數字視疲勞（也被稱為“計算機視覺綜合征”）的癥狀。

2先說一條好消息：盡管名叫視疲勞，但它并非物理性損傷，也沒有對眼睛造成長期傷害的風險。盡管如此，視疲勞也不是鬧著玩的，它可能會讓數字時代的生活變得困難。好在采取一些簡單的步驟，就可以預防或消除這些癥狀。

數字視疲勞的原因

3費城兒童醫院的眼科醫生普里揚卡·庫馬爾說，不看屏幕的時候，人大約每四秒眨一次眼。每次眨眼都會新擠出一層眼淚，而這眼淚是油脂、水分和黏液的混合物，可以潤滑和保護眼球。庫馬爾說，使用屏幕時，我們眨眼的次數會減少一半左右。這會導致我們的眼睛產生干澀感或沙礫感，甚至可能有刺痛感、灼燒感，或涌出淚水。這時的淚水不同于平常眨眼時分泌的淚水，是在大腦意識到眼睛太干時產生的。這種淚水的成分主要是水，所以往往很快就會蒸發。庫馬爾說：“流淚其實暗示了眼睛干澀?！?/p>

4頭痛和視力模糊有時與數字視疲勞相關，但它們的產生有另外的根本原因?；ê脦讉€小時看屏幕會導致負責協調雙眼的肌肉感到疲勞，因為眼肌需要長時間不斷地將我們的視線集中在相同的距離上。亞拉巴馬大學視光學院教授凱瑟琳·魏澤說：“這就像一整天都在跑馬拉松。”她還說，如果看屏幕的時間足夠長，任何人都會出現這一系列特殊癥狀，但眼部協調方面有潛在問題的人尤其容易受影響。因此，如果你感到頭痛和視力模糊，如果你發現遮住一只眼睛之后更容易將視線聚焦在屏幕上，那最好去檢查一下眼睛，看看是否確實存在潛在的眼部協調問題，魏澤如是說。

看屏幕太久會傷眼

5對于成年人來說，視疲勞可能會帶來痛苦和不便，但不會對眼睛造成實際損害。然而，庫馬爾說，對于八歲以下的兒童來說，情況就不同了。這是因為他們的眼肌還沒有發育完全。有證據顯示，長時間看屏幕會導致近視。一些研究表明，在新冠疫情期間，近視在兒童中變得更加常見，這可能是因為他們花了大量時間進行線上學習。美國醫學會專科雜志《眼科學紀要》刊載的一項研究發現，近視患病率提高了三倍之多。通常情況下，近視可以通過配眼鏡或隱形眼鏡來矯正。但在極端情況下，近視可能導致視網膜脫落，這種損傷通常會導致失明。

預防視疲勞

6幸運的是，保護眼睛免受屏幕使用時間的影響并不難，而且相關措施可以和你的日常生活無縫融合。庫馬爾說，最重要的一步是休息。她提倡20—20—20—2 法則：每隔20分鐘，盯著20 英尺外的東西至少20 秒，并嘗試一天花兩個小時待在戶外。

7將電腦顯示器放在合適的位置也很重要。庫馬爾說，應該把屏幕放置在離眼睛大約兩英尺的地方，比你不用傾斜頭部時視線自然停留的地方高幾英寸。如果比這個距離更近，你的眼睛就得付出額外的努力。

8庫馬爾說，如果你已經感覺到眼干或者眼睛有灼燒感，人工淚液可能會有所幫助。如果你戴的是隱形眼鏡，至少在你工作的時候試著換成普通眼鏡。隱形眼鏡實際上會加重干眼癥狀。

9最后，魏澤說還應該避開眩光。眩光不是沿著一條清晰路徑直射視網膜的中心，而是在眼睛周圍來回彈跳，使眼睛難以聚焦。這使得眼睛內部的肌肉（比如負責擴張瞳孔的肌肉）過度疲勞。要確保環境光線與來自屏幕的光線相似，好讓你的眼睛避開眩光。要減少在戶外的工作，關閉明亮的頂燈，還要避免在昏暗的條件下工作。魏澤補充說，帶有防反射涂層的眼鏡也有助于減少受眩光刺激。

10采取這些措施后，不要指望立竿見影。匹茲堡大學醫學院眼科教授斯科特·德雷克斯勒說，如果你已經感受到視疲勞的影響，可能需要過一段時間才能恢復正常。所幸你不需要完全遠離屏幕。從視疲勞中恢復的方法和預防的方法差不多。幾天后你應該就會感覺好多了。

防藍光眼鏡值得入手嗎？

11有關藍光的負面影響已經有很多宣傳了。一些驗光師和配鏡師聲稱藍光會損害視網膜，可能導致長期的視力問題。這些說法有一些研究結果作依據，但美國眼科學會以證據不足為由，不建議使用防藍光鏡片。

12毫無疑問，部分藍光是有害的，例如來自太陽的紫外線會導致黃斑變性和癌癥，但并不是所有的藍光都同樣有害。魏澤說，我們的電子設備不會產生紫外線，而且我們使用這些設備時接觸到的藍光總量其實相當少。她補充說，如果你擔心眼睛的長期健康，那么比起在電腦前工作時佩戴防藍光眼鏡，買一副高質量的防紫外線（UVA/UVB）太陽鏡在你長時間暴露在陽光下時佩戴，這樣更有用。 □

From Netflix binges to Zoom meetings, the coronavirus pandemic significantly increased the amount of screen time in our daily lives. All that time on devices can be taxing on the eyes—so if you’ve experienced more headaches, eye fatigue, or blurred1blurred 模糊不清的。vision, since remote work began, you’re not alone. These are symptoms of digital eye strain, also known as “computer vision syndrome”.

2Here’s the good news first: Despite its name, eye strain isn’t a physical injury and doesn’t carry any risk of longterm damage to the eyes. Still, it’s no fun, and can make life difficult in the digital age. Fortunately, there are simple steps you can take to prevent, or recover from, these symptoms.

What causes digital eye strain?

3When we’re not looking at screens,humans blink about once every four,says Priyanka Kumar, an ophthalmologist at the Children’s Hospital of Philadelphia. Each blink squeezes out a layer of fresh tears, a mixture of oil, water,and mucus that lubricates and protects the eye. When we use screens, we blink about half that much, Kumar says. This can cause our eyes to feel dry or gritty.They might even sting, burn, or tear up.These tears are different from the ones our eyes would normally produce when blinking—they’re made when our brain realizes our eyes are too dry and because they’re mostly water, they tend to evaporate quickly. “Tearing is actually a nudge that the eyes are dry,” Kumar says.

4The headaches and blurred vision sometimes associated with digital eye strain have a different root cause.Spending hours on screens can cause the muscles that coordinate our eyes to tire from the constant motion of focusing our sight on the same distance for a long period of time. “It’s like running marathons all day long,” says Katherine Weise, a professor at the University of Alabama school of Optometry. Enough screen time can cause anyone to develop this particular set of symptoms,but people who have an underlying issue with eye coordination are especially vulnerable, Weise says. So if headaches and blurred vision are your problem,if you find it easier to focus on your screen when you cover one eye, it’s probably a good idea to get your eyes checked out, in case you do have an underlying problem with eye coordination,Weise says.

When screen time causes harm

5For adults, eye strain can be painful and inconvenient, but it doesn’t cause actual damage to the eye. For children younger than eight-years old, though,it’s a different story, Kumar says. That’s because their eye muscles haven’t fully developed. There’s some evidence to suggest that lots of screen time can contribute to nearsightedness. Some studies suggest that nearsightedness has become more common in children during the COVID-19 pandemic, likely due to all that time spent learning virtually. One study, published inJAMA Ophthalmology, found that the increase was as much as three-fold. Usually, this condition is treatable with a prescription for glasses or contact lenses. But in extreme cases, nearsightedness can lead to retinal detachment, an injury that often results in blindness.

Preventing eye strain

6Luckily, protecting the eyes from screen time isn’t hard and can seamlessly fit into your daily routine. The most important step is to take breaks,Kumar says. She encourages the 20-20-20-2 rule: Every 20 minutes, look at something 20 feet away for at least 20 seconds, and try to spend two hours of the day outside.

7Placing your monitor in the proper location is also key. Set up your screen roughly two feet from your eyes and a few inches above where your sight naturally rests without tilting your head,Kumar says. Any closer, and your eyes will work harder than they need to.

8If you’re experiencing dryness or burning, artificial tears might help, Kumar says. And if you use contact lenses,try switching to glasses, at least while you’re working—contact lenses can actually exacerbate2exacerbate 使惡化，使加劇。dry-eye.

9Finally, avoid glare, Weise says.Rather than shining in a clear path straight to the center of our retina, glare pinballs around our eye, making it difficult for our eyes to focus. That overworks the muscles inside our eye, such as those that dilate the pupils. Give your eyes a break from glare by making sure that your ambient light is similar to the light coming from your screen—limit the work you do outside and switch off bright overhead lights, but also avoid working in low-light conditions. Glasses with anti-reflective coating can also help limit your exposure to glare, Weise adds.

10Once you’ve begun implementing these strategies, don’t expect instant relief. If you’re already feeling the effects of eye strain, it could take some time to feel back to normal, says Scott Drexler, a professor of ophthalmology at the University of Pittsburgh School of Medicine. Fortunately, you don’t need to take a complete hiatus from screen time. Recovery from eye strain looks similar to prevention. You should start to feel better in a few days.

Are blue-light filtering lenses worth the investment?

11Much has been made about the negative effects of blue-light. Some optometrists and opticians claim that blue-light damages the retina, which can lead to long-term vision problems. These claims are based on a few studies, but the American Academy of Ophthalmology doesn’t recommend the use of blue-light filtering lenses, citing insufficient evidence.

12Without a doubt, some blue light is damaging. Take, for instance, the ultraviolet rays from the sun, which can cause macular degeneration and cancer. But not all blue-light is equally harmful. Our devices don’t produce ultraviolet light,and the total amount of blue-light they do expose us to is actually fairly minimal,Weise says. If you’re concerned about your long-term eye health, a high-quality pair of UVA/UVB3UVA/UVB 長波紫外線/中波紫外線，穿透力較強，大量照射會對人體造成傷害。-filtering sunglasses to wear when you spend long periods of time in the sun, is a much better investment than blue-light filtering lenses for computer work, she adds. ■