UV vision

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

Found this on sci.optics, quite interesting:


xxxxxxxxxxxxxxxxx
FROM: memullen@xxxxxxx (Michael E. Mullen)
SUBJECT: Re: Seeing infrared
DATE: Mon, 02 Dec 1996 14:11:27 GMT
ORGANIZATION: Fort Wayne Internet

blaine@xxxxxxxxxxxxxxxxxxxxxx () wrote:

>Molhant Norman (molhant@xxxxxxxxxxxxxxxx) wrote:
>: Also what is the color of the sodium double line (that's the light coming from
>: low pressure sodium vapour light bulbs)?  Most people and most books tell me
>: it is yellow.  I see it orange (like the fruit).
>: And many people admire the dark blue colors of stuff that I see black, while
>: I like the strange colors of dark embers that most people see black...  I'm
>: sorry to say that I know no name for these.  ;^)

>Infrared, perhaps?

>A question for experts:  Is it physically possible for humans, at least
>some humans, (mutants?) to see infrared?

SNIP

Not IR, but Ultraviolet.

My college roommate had cataracts as a child, and had his lenses
removed.  When he was taking optics, and measuring the various
spectral lines, his labmate could not find one of the lines he was
measuring, nor could the instructor.  The instructor checked the
tables and found it to be well into the ultraviolet.  
        Roomie had also complained for years that mercury vapor streetlights
gave him headaches, and, after this event, found that sunglasses (at
night) helped a lot.
        A bit of research showed that the lens filters the UV, which causes
the retina to fluoresce.  That is, the eye cannot see the UV, but sees
the blue fluorescence.   The eye is not chromatically corrected well
for the UV, so focussing is poor (hence the headaches).

Asimov discusses the 4-F janitor (guess why) in WWII who wandered into
a lab, illuminated only by UV, and started cleaning.  Found himself
classified SECRET.  I also recall - no longer remember the source -
that a similarly 'disabled' tourist directed Israeli counterbattery
fire at camo'd Syrian gun positions - which were quite obvious in the
UV.

Crossposted to sci.optics, for inputs from those who know more...

Mike Mullen
--
Michael E. Mullen
MEMullen@xxxxxxx and others...

--
Bye,

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      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]

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Topic No. 10