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    Re: Star sparkle in sextant image
    From: Jim Thompson
    Date: 2004 Sep 27, 16:24 -0300
    Jared, your post is very interesting.  The simulators on that website are useful too.  After playing with them I conclud that my vision quality is not bad, just not perfect.  Obviously many suffer signficant impairment. 
     
    I have worn weak prescription glasses for near-sightedness since age 12, and weak reading glasses since the early 40's (still only 1.25).  I did not start using a sextant seriously until a couple of years ago, after I had had laser surgery for minor retinal degenerative changes.  I am left with what I think is no change vision in my right eye (subjectively), and a faint halo effect in my left eye, which had the floaters that lead to the diagnosis.  I use my right eye for sextant sights. Since I have no way to compare with my vision in my younger years, then presumably my ability to detect fine features through the sextant is somewhat impaired, compared to young navigators.  However I got a 0.6 mile intercept on Saturday from the boat at anchor, so I am far from blind. I could get us across the open Atlantic, but I would certainly want GPS for landfall and the channels!.
     
    It would be fun to have a simulator like that for sextant observers, so that we could construct what we see for comparisons' sake.  I wonder if the Navy has public data, or even standards, on navigator sextant vision?

    Jim Thompson
     

     -----Original Message-----
    From: Navigation Mailing List [mailto:NAVIGATION-L{at}LISTSERV.WEBKAHUNA.COM]On Behalf Of Jared Sherman

    You might want to play with the interactive vision simulator at http://www.surgicaleyes.com  .... 
       
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