# 试试这个方法。
## How to use the 20-20-20 rule
When following the rule, a person takes a 20-second break from looking at a screen every 20 minutes. During the break, the person focuses on an object 20 feet away, which relaxes the eye muscles.
Alternately, a person can benefit from closing their eyes for 20 seconds every 20 minutes. Also, remembering to blink can prevent dry eye by encouraging tear production.
## What evidence supports the 20-20-20 rule?
Little scientific research has tested the effectiveness of the 20-20-20 rule, but both the American Optometric Association (
https://www.aoa.org/documents/infographics/SYVM2016Infographics.pdf) and the American Academy of Ophthalmology (
https://www.aao.org/eye-health/tips-prevention/computer-usage) recommend it as a way to reduce eye strain.
Results of a 2013 study (
https://www.nepjol.info/index.php/NEPJOPH/article/view/8707) involving 795 university students suggested that those who periodically refocused on distant objects while using the computer had fewer symptoms of computer vision syndrome, which include eye strain, watering or dry eyes, and blurred vision.