24Drs好健康報:瞇著眼看電腦螢幕會傷害眼睛？
好健康熱頭條 ─ 瞇著眼看電腦螢幕會傷害眼睛？ Squint at Computer Screen: Eye Risk?
好健康小單字─假性近視(pseudomyopia)
好健康熱頭條 ─ 瞇著眼看電腦螢幕會傷害眼睛？
越是瞇著眼看電腦螢幕，對眼睛的傷害就越大。
最新的研究顯示，越來越多人瞇著眼看電腦螢幕，這些人眨眼的次數變少，並且自己表示眼睛疲勞、眼睛乾乾的、疼痛、以及流眼淚等症狀變多。
研究人員發現，瞇著眼看電腦螢幕會讓人每分鐘眨眼的次數比平常人少一半，這可能會導致一種具刺激性但可以治療的乾眼症。
俄亥俄州立大學驗光系教授James Sheedy在新聞稿中表示，當人們在看書或是看電腦時容易會瞇著眼看，這樣會造成眨眼次數變少；眨眼會讓眼睛濕潤，所以如果你的工作需要看很多東西，或者是非常傷眼力時，眨眼的次數可能會比正常少許多，這樣會造成眼睛疲勞與乾澀。
《在連續工作前眨眨眼》
在這篇刊載於驗光與視力科學(Optometry and Vision Science)期刊中的研究，研究人員讓10位視力正常的大學生瞇著眼看兩呎前的電腦螢幕，並且用照相機與電極記錄他們眨眼的頻率；在五次不同的測試中，研究人員計算這些學生在休息與專心看電腦時，各種不同瞇眼程度的次數，從幾乎沒有瞇眼到瞇一半。
結果顯示，即使是輕微的瞇眼也會讓眨眼次數減少一半，從每分鐘15次變成每分鐘7.5次；瞇眼程度最嚴重的學生，其眨眼率只有每分鐘四次。
研究人員表示，瞇眼有兩個目的，讓視力增加以辨別失焦的物體，以及減少強光的光度。
瞇眼經常是非自願性的反應，研究人員表示，人們在用電腦工作時，可能不知道他正在瞇眼睛；他們表示，需要做更多的研究，來判斷非自願性瞇眼是否會像自願性瞇眼一樣，大大地影響眨眼次數。
但是這些結果指出，瞇眼可能會增加眼睛疲勞與眼睛乾澀的風險，乾眼通常會用不需處方箋的眼睛潤滑劑治療。
Squint at Computer Screen: Eye Risk?
The more you squint at a computer screen, the more you may be putting your eyes at risk.
A new study shows the more people squint at a computer screen, the less they blink, and the more they reported symptoms like eye strain, dryness, irritation, and tearing.
Researchers found squinting at a computer screen halves the normal number of times a person blinks per minute, which could lead to an irritating but treatable condition called dry eye.
"People tend to squint when they read a book or a computer display, and that squinting makes the blink rate go way down," says researcher James Sheedy, professor of optometry at Ohio State University, in a news release. "Blinking rewets the eyes. So if your job requires a lot of reading or other visually intense work, you may be blinking far less than normal, which may cause eye strain and dry eye."
Blink Before Continuing
In the study, published in Optometry and Vision Science, researchers had 10 college students with normal vision squint at a computer screen placed two feet in front of them while cameras and electrodes recorded how often they blinked.
In five different tests, researchers measured how often the students blinked while at rest or engaged in deliberate squinting at various increments, from barely squinting to eyes closed about halfway.
The results showed even a slight degree of squinting cut blink rates in half, from about 15 blinks a minute to 7.5 blinks a minute. That rate was cut to just four blinks per minute when the students were squinting at the highest level.
Researchers say squinting serves two purposes: it improves eyesight by defining objects that are out of focus, and it cuts down on brightness from sources of glare.
Squinting often occurs as an involuntary response, and researchers say people working at a computer may not even realize they are squinting. They say more research is needed to determine if involuntary squinting affects blink rates as drastically as voluntary squinting, as measured by this study.
But these results suggest that squinting may increase the risk of eye strain and dry eye. Dry eye is usually treatable with over-the-counter lubricating eye drops.
SOURCES: Sheedy, J. Optometry and Vision Science, October 2005; vol 82: pp 905-911. News release, Ohio State University.
WebMD Medical News
by Jennifer Warner
Reviewed By Louise Chang
好健康小單字─假性近視(pseudomyopia)
所謂的假性近視是由於長時間看近距離的物體，睫狀肌過度收縮暫時無法放鬆，導致水晶體變厚，使屈光能力增強所造成短暫性的近視狀態；雖然只是一種暫時性的近視狀態，但它的發生往往是許多近視的前兆。
想看更多好健康的資訊嗎? 請上24Drs國際厚生
留言列表
{{ article.title }}
