Can you trust your sunglasses?

Name: Can you trust your sunglasses?
Uploaded: 2014-06-26T14:25:54.000Z
Duration: 2 min 15 s
Description: Scientists in Brazil have developed a quick way to make sure your sunglasses are protecting your eyes from the sun's harmful rays.

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Many sunglasses carry symbols saying that they protect your eyes from the sun's harmful UV rays.

But can you trust what they say?

Scientists in sunny Brazil have developed a quick way for you to be really sure, as Ben Tavener reports.