| Catching Cataracts Early - Science Insider
Reported September 2009
WHAT IS A CATARACT? Cataracts are a clouding of the eye's lens due to damaged proteins. They cause vision loss and eventually blindness. The word cataract is derived from a Latin word meaning waterfall. Like rapidly falling water, cataracts appear vaguely milky within the eye and result in a partial to complete obstacle to clear vision. Primary causes include long-term exposure to ultraviolet light, along with disease like diabetes and hypertension.
WHAT ARE LASERS: "Laser" stands for Light Amplification by Stimulated Emission of Radiation. It describes any device that creates and amplifies a narrow, focused beam of light whose photons are all traveling in the same direction, rather than emitting every which way at once. Laser light contains only one specific color, or wavelength. Because every photon is traveling in the same direction, the light is tightly focused into a concentrated beam, unlike the light emitted from a flashlight, where the atoms release their photons randomly in all directions.
There are several different types of lasers. Solid-state lasers use crystals, such as ruby. Carbon dioxide lasers emit energy in the far infrared and microwave regions of the spectrum. This type of laser produces intense heat, and is capable of melting through objects. Conventional diode lasers are the type used in pocket laser pointers and CD and DVD players.
If you would like more information, please contact:
Jean Horrigan
Media Relations
National Eye Institute
(301) 496-5248
jh@nei.nih.gov
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