Path: utzoo!utgpu!watserv1!watmath!att!cbnews!military From: tow@arisia.Xerox.COM (Rob Tow) Newsgroups: sci.military Subject: Re: Help with Cat's Eyes Cunningham Summary: Not as silly as you think. Keywords: vision infrared vitamin A navy perception diet Message-ID: <1990Jul12.025714.19077@cbnews.att.com> Date: 12 Jul 90 02:57:14 GMT References: <1990Jul8.053618.8521@cbnews.att.com> Sender: military@cbnews.att.com (William B. Thacker) Organization: Xerox Palo Alto Research Center Lines: 50 Approved: military@att.att.com From: tow@arisia.Xerox.COM (Rob Tow) In article <1990Jul8.053618.8521@cbnews.att.com> boebert@SCTC.COM (Earl Boebert) writes: > >Well, it seems I posted an item to a different newsgroup about the >British deception in WWII where they attempted to cover the existence >of airborne radar by putting out news stories that a combination of >testing and lots of carrots had improved their pilot's night vision. >(This because the night fighters were suddenly significantly more >effective.) The premise of the story is not as silly as it seems; read the account below to see! "The following story dramatizes how your photopigments determine what you can see. During World War II, the United States Navy wanted its sailors to be able to see infrared signal lights that would be invisible to the enemy. Normally, it is impossible to see infrared radiation because, as was pointed out earlier, the wavelengths are too long for human photopigments. To see infrared, the spectral sensitivity of some human photopigments would have to be changed. Vision scientists knew that a derivative of vitamin A was part of every photopigment molecule and that various forms of vitamin A existed. If the retina could be encouraged to use some alternative form of vitamin A in its manufacture of photopigments, the spectral sensitivity of those photopigments would be abnormal, perhaps extending into the infrared. Human volunteers were fed diets rich in an alternative form of vitamin A but deficient in the usual form. Over several months, the volunteers vision changed, giving them greater sensitivity to light of longer wavelengths. Though the experiment seemed to be working, it was aborted. The development of the "snooperscope", an electronic device for seeing infrared radiation, made continuation of the experiment unnecessary (Rubin and Walls, 1969). Still, the experiment demonstrates that photopigments select what one can see; changing those photopigments would change one's vision." -"Perception", by R. Sekuler and R. Blake, Alfred A. Knopf, 1985, ISBN 0-394-32815-9, pp. 58-59. --- Rob Tow Member Research Staff Electronic Document Lab Xerox PARC 3333 Coyote Hill Drive Palo Alto, CA 94304 (415)-494-4807