The exercise is found to decrease the risk of macular degeneration and cataracts in two studies of regular runners.

Add vision protection to exercise's list of benefits.

In two new analyses based on the National Runners' Health Study, one found that people who ran an average of 2 to 4 kilometers a day (1 mile equals 1.6 kilometers) had a 19% decrease in their risk of age-related macular degeneration, when compared with people who ran less than 2 kilometers per day. Those who ran more than 4 kilometers per day had a 42% to 54% decrease in risk. The other analysis found that men who ran 64 or more kilometers a week had a 35% lower cataract risk than those who ran less than 16 kilometers per week. Paul T. Williams, a staff scientist with the U.S. Department of Energy's Lawrence Berkeley National Laboratory and author of both studies, believes that exercise could provide similar protective benefits for the eyes as it does for the heart and other systems.

"There are overlaps," he says. The study appeared in January's Investigative Ophthalmology & Visual Science.

两项在经常跑步的人群中开展的调查显示，这项运动可降低黄斑变性和白内障的发病几率。

经常运动的好处多多，现在可以把“保护视力”也算进去了。

近期，研究人员基于全国跑步者健康调查进行了两项分析。其中一项分析结果显示：与每天跑步少于2公里的人相比，平均每天跑2至4公里（1英里约合 1.6公里）的人患上与年龄相关的黄斑变性的风险可降低19%。而那些每天跑步4公里以上的人们患此疾病的风险要下降42%至54%。另一项分析结果显示，与每周跑步少于16公里的人相比，每周跑步64公里或更多的人们患白内障的风险可降低35%。美国能源部劳伦斯伯克莱国家实验室的科学家，同时也是这两项调查报告的起草者保罗·T·威廉姆斯认为，运功不但有益于心脏和其他器官，也同样对视力具有保护作用。

他表示，“运动的益处可以相互重叠。”这项调查报告刊登在一月份的《眼科学研究和视觉科学》上。