Why Do People Blink Their Eyes?

    People blink(眨眼) their eyes tens of thousands of times every day. Scientists have long believed blinking was an involuntary movement and served mainly to keep the eyeballs wet. But a new study suggests it has a more important purpose.

    An international team of scientists from the University of California at Berkeley studied the blinking of human eyelids. The journal Current Biology published their findings. The team said they found that blinking “repositions our eyeballs so we can stay focused” on what we are seeing. They said that when we blink our eyelids, the eyes roll back into their sockets--the bony area that surrounds and protects the eyes. However, the researchers found the eyes don't always return to the same position. They said this causes the brain to tell the eye muscles to reorganize our eyesight.

    Gerrit Maus is the lead writer of the report. He serves as an assistant professor of psychology at Nanyang Technological University in Singapore. Maus says: “Our eye muscles are quite sluggish(迟缓的) and imprecise, so the brain needs to constantly adapt its motor signals to make sure our eyes are pointing where they're supposed to. Our findings suggested that the brain measures the difference in what we see before and after a blink, and commands the eye muscles to make the needed corrections.” The researchers said that without such corrections our surroundings would appear unclear and even jumpy. They said the movement acts “like a Steadicam(摄影稳定器) of the mind.”

    The researchers said they asked volunteers to sit in a dark room while staring at a small dot on a flat surface. They used special cameras to follow the volunteer's blinks and eye movements. After each blink, the dot was moved one centimeter to the right. The volunteers did not notice this, but the brain did. It followed the movement and directed the eye muscles to refocus on the dot. After the dot was moved in this way 30 times, the volunteers' eyes changed their focus to the place where they predicted it would be.

    Professor Maus says “Even though participants did not consciously register that the dot had moved, their brains did, and adjusted with the corrective eye movement. These findings add to our understanding of how the brain constantly adapts to changes, commanding our eye muscles to correct for errors in our bodies' own hardware.”

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    After a homeless man offered a college student in England all the money he had so she'd be able to get home safely, the woman is paying it forward—in a massive way.

    The story began in early December. It was about 3 a.m. and Harrison-Bentzen was panic. “I came out after a student night out and realized I didn't have any battery on my phone. I'd lost my friends,” the 22-year-old told BBC Radio 5. She'd also lost her bank card, she discovered, and she had no money.

    Just then, a homeless man, known only as Robbie, approached the young woman and asked her if she needed help. He reached into his pocket and pulled out all the money he had—loose change amounting to about $4.60. He insisted that Harrison-Bentzen take it to pay for a taxi so she'd get home safely.

    Harrison-Bentzen, a student at the University of Central Lancashire in Preston, England, says she refused to take Robbie's money and found another way to get home. But following her encounter（偶然相遇）with the generous man, she says she couldn't get him out of her mind.

    For the next few days, the student searched for Robbie, driving around the streets with her mom and using social media in an attempt to locate the man. In that time, Harrison-Bentzen says she learned more about Robbie and discovered that he actually had a reputation for helping strangers.

    Finally, after four days of driving around Preston, Harrison-Bentzen found Robbie. She was determined to do something to help change Robbie's life.

    So, earlier this month, the student launched a fundraising campaign in Robbie's name. She explained that she would be spending 24 hours on the streets, so as to “understand the difficulties” that the homeless face on a daily basis.

    Harrison-Bentzen says she had initially（最初）hoped to raise about $780 with her campaign. Her expectations, however, were quickly blown out of the water. As of Thursday morning, 4,800 people have donated almost $50,000.