This episode of the Freakonomics podcast tells a story from China about a foolproof way to the increase learning potential, at least for some students.

“It doesn’t have a fancy name. You don’t need a PhD to administer it. And it’s almost comically cheap," the hosts explain. It’s glasses.

Economists Paul Glewwe at the University of Minnesota and Albert Park at Oxford learned that 10 to 15 percent of the students in Gansu China had vision problems that could be corrected with glasses, but only two percent of the kids that needed glasses actually had them.

So, they decided to put together an experiment. They set up two groups: the experiment group, kids who needed glasses were given glasses for free, and the control group, kids who needed glasses but wouldn’t get glasses (at least they wouldn’t during the experiment phase.)

Thirty percent of the kids offered glasses for free turned them down. Seriously! Beyond the general school teasing, there is a widespread perception in Gansu that wearing glasses when you’re young will weaken your eyes

But the 70 percent of students who did accept the glasses saw a definite increase in how much they were able to learn. Paul Park says that the students were very thankful and the teachers were amazed. One of the students who received glasses said, “There was clarity in the world. My grades suffered before I got the glasses, now they are slowly improving.”

In China they had a hard time getting kids to wear free glasses, but in the U.S. there has been a rise in the amount of people wearing fake glasses or “planos.”

Host Stephen Dubner speaks with Harvey Moscot, an optometrist and president of the New York eyewear shop MOSCOT about the switch glasses made from utilitarian item to a fashion item. He says to people who don’t need glasses, glasses are a fashion accessory. As he puts it:

"It could project a different image, it’s a pretty cheap pick-me-up, it sure is a lot less expensive than a face lift or a wardrobe overhaul. And it can affect one’s ability, self-esteem, how they project, image.”

Well, I need glasses, so hearing that has helped my self-esteem. I’m so trendy!

Bonus info: The work in Gansu China has been continued by Stanford University. They’ve been providing education to teachers on eyesight and have been working to dispel superstitions. You can read more here.