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Most Laser Pointers Are Too Strong
Federal researchers美國聯邦政府研究員 find
that most green laser pointers and half of red ones are stronger than safety standards permit安全標準許可, creating an eye hazard雙眼的危害.
Laser pointers雷射筆 are helpful
when giving a
presentation提案. Just don’t let the beam光束 hit you in the eye—especially when it’s green.
The National
Institute of Standards and Technology美國國家標準技術研究所
says that nearly 90 percent of commercially
available商用型 green pointers and about half
of red pointers they tested are too strong and violate違反 federal safety
regulations聯邦安全規範.
Green
lasers use a shorter wavelength較短波 of light than red ones, making them brighter and
more dangerous. The darker part of the retina
視網膜heats up灼傷 from the green laser’s intense強烈, yet invisible隱形的, infrared紅外線
light, which can cause retinal scarring視網膜灼傷 and
even blind spots(導致)視力出現中央盲點. Because the damaging
wavelengths are invisible, the eye’s natural
defense mechanism—its eyelid—doesn’t close to provide protection.
Airline
pilots are well aware of these dangers: in 2011
alone there were more than 3,500 cases of
lasers being pointed at aircraft. In July
2012 one unfortunate JetBlue 美國廉價航空捷藍pilot
suffered an eye injury when someone on the
ground shined a green laser through his cockpit飛機駕駛艙
window. Luckily, the flight landed safely.
Unluckily, it didn’t land on the person
pointing the laser.
—Larry Greenemeier
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