四眼兒不代表缺點 近視的贏家和輸家

I have worn glasses since early childhood. I often wished I didn’t have to. Sport was difficult before soft contact lenses arrived. As a rugby full back, I was a determined tackler, but a hapless spiller of the high ball.

我從小就戴眼鏡。我常常希望自己要是不戴眼鏡就好了。在軟性隱形鏡片問世前，戴眼鏡的人運動起來很麻煩。作爲橄欖球后衛，我是一個頗爲執着的攔截者，但在捉高球方面我就不那麼走運了。

The name-calling — “goggles”, “four-eyes”, “prof” — was annoying, but left no lasting scars. The sharp-tongued ripostes you develop are useful in all areas of life.

“眼鏡”、“四眼”、“教授”這樣的綽號很煩人，但也沒有給我留下什麼永久性傷害。還擊中練就的伶牙俐齒倒是在生活中的各個方面都挺有用的。

As a myope, I was part of a small club back then. That is not true of young people today. Of Europeans aged 25 to 29, some 47.2 per cent are shortsighted, according to a study in the Opthalmology journal.

那時我這樣的近視眼屬於一個小羣體。但對如今的年輕人來說就不是這樣了。根據期刊Opthalmology上刊登的一份研究，歐洲25到29歲的人羣中，有47.2%都是近視。

Katie Williams of King’s College London, which led the study, says that in cities in east Asia, almost 80 per cent of young people are short-sighted.

主持這項研究的是倫敦國王學院(King's College London)的凱蒂•威廉斯(Katie Williams)。她表示，在東亞的城市中，幾乎80%的年輕人都是近視。

The rise in myopia has been startling. In Europe, only 27.5 per cent of 50 to 59-year olds are short-sighted, which means the level has almost doubled in a generation.

近視人羣的漲幅令人吃驚。歐洲50到59歲的人羣中，只有27.5%是近視。這就意味着僅僅在一代人的時間裏，近視人羣的比例就幾乎翻了一番。

There are marked differences within generations. The longer people remain in education, the more short-sighted they are. Among 45 to 49-year olds, 26.3 per cent of those who left school before 16 are short-sighted. Among those who have been through higher education, the level is 51.4 per cent.

近視人羣的比例有明顯的代際差異。受教育的時間越長，近視的機率就越大。45到49歲的人羣中，16歲前就離開學校的人中有26.3%近視。受過高等教育的人羣中，近視人羣的比例達到了51.4%。

Can we attribute these results to those who think they need glasses being more likely to have their eyes tested? King’s College London says not. The Opthalmology report was based on a series of studies that tested the eyes of a representative sample of people.

這種結果是否可以歸結於那些認爲自己需要眼鏡的人更可能去測視力？倫敦國王學院的研究者們並不這麼認爲。作爲報告基礎的一系列研究採用的樣本人羣是具有代表性的。

“While there is always some element of volunteer bias in studies, the studies were mainly looking at age-related eye diseases (and often not just eye diseases) so it is unlikely that short-sighted people self-selected to participate,” the college says.

“儘管研究中總會有一些志願者偏差的因素，但是這些研究主要瞄準的是與年齡相關的眼疾（而且通常不僅是眼疾），因此不太可能是近視的人自己選擇了參加，”該學院表示。

Why are people becoming more short-sighted? The Opthalmology authors say myopia runs in families and is “highly heritable” but environmental factors play an important role too.

爲什麼人們越來越近視？研究報告的作者們表示，近視在家族中傳遞，具有“高度遺傳性”，但環境因素也起着非常重要的作用。

What those factors are is unclear. “Myopia has been associated with education, near work, urbanisation, prenatal factors, socio-economic status, cognitive ability, season of birth, light and time spent outdoors,” the researchers say.

那些因素是什麼尚不清楚。“近視同教育、近距離工作、城市化、孕期因素、社會經濟地位、認知能力、出生的季節、光線、還有在戶外待的時間有關，”研究者們表示。

The link between sight and higher education is also murky. It may be that further schooling means more reading and less time outside. It may be that there are “shared genetic factors underlying myopia and intelligence”.

視力和高等教育之間的聯繫也尚未弄清。可能是在學校待得越久，就意味着讀書更多，戶外運動越少。也可能是“在近視和智力的背後，潛藏着一些共同的遺傳因子”。

What is clear is that the explosive rise in myopia will have long-term consequences. Having to wear glasses or contact lenses is just the start. As we get older, shortsighted people are more likely to suffer from retinal detachment, glaucoma and cataracts.

有一點是很清楚的，那就是近視人羣的爆炸性增長將會造成長期影響。不得不戴眼鏡或者隱形眼鏡僅僅是開端。隨着年齡增長，近視人羣更可能受到視網膜脫落、青光眼和白內障的困擾。

This may not be a brewing public health crisis on the scale of the obesity epidemic, but it is pretty serious. If firmer evidence emerges that all work and no play makes Jack a dull-sighted boy, parents and educationalists will have to examine changing the balance.

或許這並不是一個醞釀中的像肥胖症流行那樣規模的公共健康危機，但也相當嚴重。如果有更切實的證據表明只工作不玩耍，就會變得近視，那麼家長和教育家就需要研究一下如何調整兩者的平衡了。

In the meantime, a problem for some means opportunity for others. The worldwide market for glasses and contact lenses is expected to grow from $81bn in 2011 to $130bn in 2018, says Transparency Market Research.

同時，一些人的問題也是另一些人的機會。據Transparency Market Research的數據，全球眼鏡和隱形眼鏡的市場規模預計將從2011年的810億美元增長到2018年的1300億美元。

That is not all because of short-sightedness. People also need reading glasses as they get older and the figure includes sunglasses.

這並不全是因爲近視。當人們變老的時候，還會需要老花鏡，而且太陽鏡也包含在該數據之中。