英语听力文摘 English Digest 172、眼睛间谍

（单词翻译）

　　Eye spy, on this moment of science. You see at a movie's, someone is asked for identification, instead of producing a badge or picture, they simply look into a camera. Hollywood special effect department then show us lots of needle computer graphics¹. They suggest a future machine that can scan the human eye or in order to positively² identify the person. The future is after all, it seems, eye scanning devises not only exists, they are being tried out in various locations around the world.
The idea behind a iris³ scanner is just what sci-fi told us it would be. Everyone’s iris is unique, and easily distinguished⁴ by modern computers from the iris of any other person on the planet. In fact, irises⁵ are more easily distinguished than either fingerprints⁷ or signatures, both of which are used today as evidence of identity. Push your finger down too hard and you can throw off a fingerprint⁶ reading device. And it’s by no means impossible to imitate another person’s signature!
But iris scans are almost impossible to fake. As you walk toward the bank teller⁸ a camera zooms⁹ in on your torso, finds your head, then finds your eye. It snaps a picture and then breaks down the iris markings into dark areas and light areas. This data is compared with a scan you put into the computer’s memory when you opened your account. Bing! You don’t even need to swipe a card.
Some systems even check for the tell-tale contraction¹⁰ and dilation¹¹ of the iris, to prove that the eye being scanned is indeed alive.