如今，人們的日常生活已經離不開電腦、手機，但這些電子產品在帶給人更多方便、樂趣的同時，也會導致眼睛疲勞、近視加深等視覺問題。
有人指出，「電子產品所發出的高能短波藍光是造成眼乾、眼澀、眼疲勞的罪魁禍首」，於是防藍光眼鏡應運而生，並且銷量不俗。
防藍光眼鏡真能保護眼睛，還是只是一個市場噱頭呢？在下結論之前，我們首先需要了解一下什麼是藍光？
Blue light is a type of electromagnetic radiation with a very short wavelength that produces a high amount of energy. While it's true that light can damage your eyes under certain circumstances, there's no scientific evidence suggesting that blue light is harmful to our eyes. But many people still think it is, which is why blue light-blocking glasses are so popular.
藍光是一種波長非常短、能量巨大的電磁輻射。雖然在某些情況下光線確實會損傷我們的眼睛，但是目前並沒有科學證據表明藍光對我們的眼睛有害。不過許多人仍然認為藍光確實有害，這就是防藍光眼鏡如此受歡迎的原因。
"Everyone is very concerned that (blue light) may be causing damage to the eye, and it's a valid concern, but there's no evidence it may be causing any irreversible damage," Dr. Rahul Khurana, clinical spokesman for the American Academy of Ophthalmologists, told Business Insider.
美國眼科學會臨床發言人拉胡爾•庫拉納博士對商業內幕網表示：「每個人都非常擔心藍光可能會對眼睛造成損害，這種擔憂是合理的，但是目前還沒有證據表明藍光可能會對眼睛造成任何不可逆轉的損傷」。
Blue light exposure is nothing new. In fact, the sun is the largest source of blue light. Moreover, blue light is also present in fluorescent and LED light.
藍光照射並不罕見。事實上，太陽就是藍光最大的來源。此外，藍光也存在於螢光燈和LED燈中。
But if blue light isn't harmful, then why are we constantly rubbing our peepers when we're looking at our screens? The answer is eyestrain: More than 60 percent of people experience problems associated with digital eyestrain. And blue light, it seems, isn't the cause. Instead, our eyes are so strained because most of us blink less when we stare at our digital devices.
但如果藍光是無害的，為什麼我們在看屏幕的時候會不停揉眼睛呢？真正的答案是眼睛疲勞：超過60%的人存在因使用電子產品導致的眼疲勞問題。而藍光似乎並不是造成這些問題的原因。我們的眼睛之所以會如此疲憊，是因為大多數人在盯著電子產品時，眨眼的次數會減少。
So if eyestrain is the real issue, blue light-blocking glasses are probably useless. However, wearing them could potentially help you get a good night's sleep. That's because blue light, research has shown, affects your body's circadian rhythm, your natural wake and sleep cycle. According to Harvard researchers, any kind of light — including blue light — can tamp down your body's ability to secrete melatonin, a hormone that helps you sleep.
也就是說，如果眼疲勞才是真正的問題，那麼防藍光眼鏡可能是無用的。不過，戴上它也許可以幫你改善睡眠。因為研究表明，藍光會影響人體的晝夜節律，即生物鐘。據哈佛大學的研究人員稱，任何一種光（包括藍光）都會降低人體分泌褪黑素的能力，而褪黑素正是一種幫助你入眠的激素。
除了防藍光眼鏡，網絡上還流傳著許多關於保護眼睛的方法，比如下面這個「豆沙綠的桌面」。
據科普網站果殼網稱，將電腦設置成「豆沙綠」唯一可能做到的只是讓屏幕亮度變得不那麼刺眼。對於由眨眼次數少使淚液蒸發過快造成的乾眼，坐姿、與屏幕距離等問題造成的視疲勞、上身疼痛，「豆沙綠」是沒有任何效果的，靠這個操作保護視力不靠譜。
那麼長期使用電腦的你，應該如何保護雙眼呢？我們整理了幾條小貼士：
Position your screen 20-30 inches away from your face, and make sure your eyes are level with the very top of your monitor. The key thing to remember is that you should be looking slightly down at your work. The center of the screen should be located between 15 and 20 degrees below horizontal eye level.
將屏幕放在距離臉部50-70釐米的位置，確保你的眼睛與屏幕頂部齊平。記住，關鍵是當你看屏幕時視線應該是稍微向下傾斜的。屏幕中心應該位於水平視線以下15到20度之間。
Follow the 20-20-20 rule. Look away from your screen every 20 minutes for 20 seconds at a time and focus on a fixed point 20 feet away.
遵循20-20-20法則。每隔20分鐘將視線從屏幕前移開，盯著20英尺（約6米）外的一個固定點看20秒。
Most monitors let you adjust the color temperature manually. It's best to use a warmer (yellowish) color temperature in dark rooms and a colder (bluer) color temperature in bright rooms.
大多數顯示器可以手動調節色調。最好在黑暗的房間裡使用偏暖色調（偏黃），在明亮的房間裡使用偏冷色調（偏藍）。
來源：howstuffworks.com，Wired，果殼網
編譯：董靜
審校：yaning