在光線暗處看書真的對眼睛有害嗎
Mom always told us we'd go blind if we read in the dark. Does science back her up? Jim Sheedy, a doctor of Vision science and director of the Vision Performance Institute at Oregon's Pacific University, sets his sights on the truth.
媽媽總是告訴我們如果我們在暗處看書會弄壞眼睛。這種說法有科學依據嗎？且聽俄勒岡太平洋大學(Pacific University)視覺功能學院(Vision Performance Institute)所長、視覺科學醫生吉姆?希迪(Jim Sheedy)爲我們揭示真相。Dark Matter
暗處閱讀Turns out, our parents were wrong. 'There is no reason to believe nor evidence to support that any long-term damage to the eyes or change in the physiology to the eyes can be caused by reading in the dark,' Dr. Sheedy says。
原來，我們的父母是錯的。希迪博士說：“我們沒有理由認爲，也沒有證據證明，在暗處閱讀會造成眼睛的長期損害，或引起眼睛的生理變化。”
That is not to say that nocturnal page-turning won't lead to discomfort or fatigue。
但這並不意味着在夜間昏暗光線下看書不會引起不適和疲勞。The lack of light will cause the pupils to dilate, resulting in a smaller depth of field -- the distance between the nearest and farthest object that the eye considers to be in focus. Dr. Sheedy says the added effort to change focus (called the eye's accommodative system) and the effort to change the angle of the lines of sight between the two eyes (called the vergent system) will likely make your eyes feel tired and your body spent. But, of course, that's often the object of reading under the covers。
光線不足會引起瞳孔擴張，導致景深變小，即眼睛能聚焦的最近和最遠的物體之間的距離變小。希迪博士說，費力地去變焦(通通過眼睛的調節系統)和費力去地改變兩眼之間的視角(通過眼睛的收縮系統)可能會使你的眼睛和身體感到疲倦。當然，這通常是在被窩裏看書的後果。Seeing Clearly
看清楚Dr. Sheedy says he assures his students that there isn't enough evidence to argue that what you do with your eyes leads to myopia (nearsightedness)： 'The predominant determinant of myopia is genetics.' No link to long-term damage has ever been conclusively shown, says Dr. Sheedy. 'It's an old tale, a ploy used by moms to get kids to go to sleep when they wanted them to,' he says。
希迪博士說他告訴他的學生現在還沒有足夠的證據能說明用眼習慣會導致近視：“近視的主要決定因素是遺傳。”他說並沒有確鑿的證據證明長期損害跟近視之間存在關聯。希迪博士說：“這只是一個古老的傳說，是媽媽們希望孩子們去睡覺時常用的一個說辭。”Electronic Age
電子時代Reading on a tablet device won't damage your eyes, Dr. Sheedy says. His team has studied various fonts, computer displays and pixel resolutions, and found the difference in effect on the eye between reading e-ink and the printed word to be negligible。
希迪博士說，在平板設備上閱讀文字不會傷害眼睛。他的團隊對各種字體、電腦顯示器和像素分辨率進行了研究，發現閱讀電子讀物和印刷文字對眼睛影響的差異是可以忽略不計的。He adds that pixel density and screen resolution have reached the point at which the eye doesn't know which it is seeing. So if reading a printed book in dim light is fine, so is reading a Kindle or iPad。
他補充說，像素密度和屏幕分辨率已經發展到了讓眼睛分辨不出電子讀物和印刷文字之間差異的程度。如果在昏暗的光線下閱讀印刷書籍沒什麼問題的話，在Kindle或iPad上閱讀也不會有問題。Moving from Dark to Light
從暗處到亮處The eyes adapt quickly when going to the light -- emerging from a tunnel into the sun, say -- but going to the dark 'requires the regeneration of photo pigments, and that takes some time to reach full dark-adaptation,' says Dr. Sheedy。
希迪博士說，從暗處到亮處時眼睛適應起來非常快，比如從隧道里出來重見天日時，但從亮處到暗處時“需要新生成光色素，因此需要一些時間來完全適應黑暗”。Adjusting to the dim light next to your bed should only take seconds. But when going from bright light to maximum darkness, studies have shown, eye sensitivity continues to change for up to 25 minutes, he says。
他說，你對自己牀邊暗光燈的光線的適應只需要幾秒鐘的時間。但有研究表明，如果從亮如白晝轉到漆黑一片，眼睛的感光度要持續變化長達25分鐘的時間。Just ask a pirate。
問問海盜吧'Ever wonder why a pirate wears patches? It's not because he was wounded in a sword fight,' says Dr. Sheedy. Seamen must constantly move between the pitch black of below decks and the bright sunshine above。
希迪博士說：“想知道爲什麼海盜總是戴着眼罩嗎？這並不是因爲他在劍戰中受了傷。”真正的原因是水手必須經常在漆黑的甲板下和明亮的陽光下這兩處地方之間變換位置。Smart pirates 'wore a patch over one eye to keep it dark-adapted outside.' Should a battle break out and the pirate had to shimmy below, he would simply switch the patch to the outdoor eye and he could see in the dark right away -- saving him 25 minutes of flailing his cutlass about in near blindness。
聰明的海盜“在一隻眼睛上戴着眼罩，就能保證有一隻眼睛始終能適應黑暗。”如果戰鬥爆發，海盜必須轉戰到甲板下面，他只需要把眼罩換到另一邊，就可以馬上在黑暗中恢復視力──這樣一來他就不用在近乎失明的情況下揮劍戰鬥25分鐘了。
