Blue light

Part of the 5th Special Forces Group that existed into the early 1980s. According to Col. Charles Beckwith's memoirs (2000), this counter-terrorist group was formed by U.S. Army Special Forces leadership who disagreed with or felt politically threatened by Beckwith's Delta Force. The unit was supposedly disbanded when Delta went operational; rumored to still exist under same name or covert black ops name.
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light rays which can be even more dangerous to the retina than ultraviolet, in that they cause production of free radicals.
For more information, read  Blue Light and Macular Degeneration in the MD Support Library.